MARINE BIOLOGICAL LABORATORY.

Received July 20, 1939

Accession No. 5049&

Maomil an Co.
Given by

Place, New Jork City

***rlo book op pamphlet is to be removed from the Liab-
opatopy taithout the pepmission of the Trustees.

THE MYXOMYCETES

By THOMAS H. MACBRIDE

THE NORTH AMERICAN SLIME-MOULDS

THE MYXOMYCETES

A DESCRIPTIVE LIST OF

THE KNOWN SPECIES WITH SPECIAL REFERENCE
TO THOSE OCCURRING IN NORTH AMERICA

BY
THOMAS H. MACBRIDE

AND

G. W. MARTIN

STATE UNIVERSITY OF IOWA

NEW YORK

THE MACMILLAN COMPANY
1934

Copyright, 1934, by
THE MACMILLAN COMPANY.

All rights reserved — no part of this book may be
reproduced in any form without permission in writing
from the publisher, except by a reviewer who wishes
to quote brief passages in connection with a review
written for inclusion in magazine or newspaper.

Set up and printed
Published May, 1934.

PRINTED IN THE UNITED STATES OF AMERICA

"Willst du dich am Ganzen erquicken,
So musst du das Ganze im kleinsten erblicken."

"Benutze redlich deine Zeit,
Willst was begreifen, such nicht weit."

Goethe.

"Diese Kinder der Natur, welche aus einer ungeformten
Gallert, und einem unsichtbaren Saamen entstehen, sind im
stande, in dem sie sich nach und nach entwickeln, und ihre
scheinbar nachlassige Bildung genau beobachten (kssen),
eben so sehr als die schonste Pflanze, einem empfindenden
Herzen die tiefe Achtung und das paradiesische Vergnugen
zu verschaffen, welches einzig die Betrachtung der Heere der
Natur und ihre gleichbleibende Erhaltung durch eine ewige
Kraft hervorbringen kann."

A. J. G. C. Batsch (1783).

PREFATORY NOTE

Taxonomy, the art of classification applied particularly to animals
and plants, is conditioned largely upon structure. This, we soon learn,
is the outcome of experience, the record obverse of history of a bit of
life, so that correct taxonomy is reached only as we know the whole
story of the object studied.

From this point of view our art enters the most fascinating, beauti-
ful phase of science; every living thing bringing to the observer sug-
gestion of some primal, far-off beginning. This must have been! Life
pulsates; its forms follow the changes of the physical world; reach a
certain maximum as we say, then disappear, reduced to lowest terms,
to start again, — more frequently only a cell or two, which wait occa-
sion, — good or bad — to repeat the never ceasing cycle.

As far as possible taxonomy must know these things, and more;
for completion? aye for breadth of view; but more rigidly for precision,
exactness more or less possibly attained.

But Nature herself, even in minor things is endlessly inexact, so
that for any organism life's highway would seem to have been from
the beginning nor straight nor plain. But by this it does appear all
progress has been conditioned; endless change of place, of posture, of
other environment until now! That the slime mold, a simple, uncov-
ered, unprotected, filmy sheet or particle, should, astir with life, —
some dominating urge, — should have met all conditions in such good
fortune as still to cover the habitable earth in variety, in richness of
form, and directness of behavior attracting the attention of the
biologist, is a wonder indeed.

The marvel has been studied; but to modern science the myxomy-
cetes are really new; they call for quick taxonomy, possible not to
lenses only, but even in so far to the naked eye, and at this moment
they kindle lively interest around the world.

In fact a new chapter here begins, a step forward in the science of
our subject. True, we have not been able to open the gate to disclose
creation's secret, the earliest cell from which our series rises, but we
at last have opened, or at least have set ajar its homologue; we now
point to the primal cell through which each new generation passes;
we show the history of the germ from which the "cornstock" rises.
The gateway for the slime mold small indeed, its width-unit n — the
thousandth of a mm.! Yet gate it is, with all the ancient (?) furnishing;

vii

viii PREFATORY NOTE

in wondrous organization quite as in the lily or the pine, — mitosis;
and all in the nucleus as required, nucleus but a fraction of the spore !
Say we not well, a chapter but beginning?

To assist in meeting such inquiry and interest is the purpose of this
book. For this edition it has been to the writer's great pleasure and
advantage to have the assistance of his colleague, Dr. G. W. Martin :
the introduction and general editing of the text is his. By enlarging
our field of inquiry, the number of species presented has been greatly
enlarged. New plates were needed, — all our plates are new! To the
young botanists of our continent and to our contributors around the
world, the present volume is especially devoted. May they fare well !

T. H. M.

PREFACE

Doctor Macbride's death occurred in Seattle, Washington, on March
27, 1934, after a short illness, just as the final copy for the present vol-
ume was being made ready for submission to the publishers. During
the six years it has been in preparation he has taken an active part in
the work, reading and criticising the manuscript and proofs, and mak-
ing numerous suggestions, based on his long familiarity and wide ex-
perience with the organisms of which it treats. Many of these sug-
gestions have been embodied in the treatment. It has been a privilege
to have been associated with him in the work; it is a satisfaction to
record in this place his uniform kindliness and courtesy, and the in-
spiration of his rare personality.

In the very nature of the case, the task of which this is a part can
never be complete. This publication, like others of its kind, may
represent merely a milestone, marking, in so far as it is honestly and
competently wrought, a certain degree of progress toward adequate
understanding of the infinite variety of forms in which life has been
manifest. It is offered with a keen sense of its shortcomings and
limitations, but with the hope that in its turn it may serve as a new
starting point for further advance.

Of the many who have shown helpful and sympathetic interest in
the undertaking, mention can be made of only a few. Dean C. E. Sea-
shore of the Graduate College of the University of Iowa has been
most generous in the provision of research assistance. The assist-
ants themselves, Dr. Frank L. Howard, Dr. H. C. Gilbert and
Mr. Donald P. Rogers, have rendered valuable aid at successive
stages. Upon Mr. Rogers, in particular, has fallen the burden of much
of the final detail, including the checking of citations, the reading of
proof and the preparation of the index. To his intelligent perception
and keen interest I am indebted for the detection of numerous errors.
Finally, I must acknowledge the devoted assistance of my wife,
rendered in many ways throughout the progress of the work.

G. W. Martin.
Iowa City, Iowa,
March 31, 1934.

CONTENTS

Prefatory Note vii

Preface ix

Introduction 1

Subclass EXOSPORE^ 15

Subclass MYXOGASTRES 17

Order PHYSARALES 18

Order STEMONITALES 144

Order LICEALES 203

Order TRICHIALES 247

Supplementary Notes ....... 304

Appendix: Names Not Recognized in Text . . . 307

Bibliography 313

Index 323

Plates 341

50496

1^ /oos^>

INTRODUCTION

I. General Morphology

The Myxomycetes are fungus-like organisms characterized by an
assimilative phase consisting of a naked, multinucleate, mobile mass
of protoplasm, the Plasmodium, and a reproductive phase, consisting
in most instances of a membranous spore-case. The latter often con-
tains, in addition to the spores, a system of netted or free threads, form-
ing the capillitium, and frequently bears, within or without, calcareous
accretions of specific character. The spore, on germination, emits a
vesicle which gives rise to one or more swarm-spores, each with an an-
terior flagellum; or it may produce the swarm-spores directly. These
feed and multiply, eventually function as gametes and fuse in pairs
or sometimes larger groups. The zygote so produced is the first stage
of the Plasmodium. It grows, with multiplication of nuclei, and
also in some cases, perhaps usually, by combining with other Plas-
modia, and under appropriate conditions, produces the fructification.

As here presented, the Myxomycetes are regarded as constituting
the first and simplest class of the Fungi, coordinate in rank with the
Phycomycetes, Ascomycetes and Basidiomycetes. Certain members
of the group have been noted by careful observers for nearly three
hundred years. Lister cites Pankow's figure and description, 1654,
of the species now known as Lycogala epidendrum. Ray, in 1690, called
the same species Fungus coccineus etc.; Ruppenius, in 1718, Lycoperdon
sanguineum etc.; Dillenius, a year later, Bovista miniata; Buxbaum,
in 1721, Lycoperdon epidendron. In 1729, Micheli erected the genus
Lycogala for it and at the same time added recognizable descriptions
and illustrations of several other genera and even species. But Micheli's
light was too strong for his generation. As Fries, writing a century
later, says "immortalis Micheli tarn claram lucem accendit, ut suc-
cessors proximi earn ne ferre quidem potuerint." Notwithstanding
Micheli's clear distinctions, he was entirely disregarded and the little
Lycogala was dubbed Lycoperdon and Mucor down to the end of the
century. It was not until 1794 that Persoon came around to the
standpoint of Micheli and wrote Lycogala miniatum. Fries himself,
reviewing the labors of his predecessors, grouped the slime molds as
a suborder of the Gasteromycetes, although clearly recognizing the
peculiar character of their assimilative phase, and gave expression to

l

2 THE MYXOMYCETES

his view of their nature and position when he named the suborder
Myxogastres. In 1833, Link, perceiving more clearly the distinctness
of the group, substituted the name Myxomycetes. Wallroth used the
name in the same year and he is usually credited with it, but he seems
strangely to have confused its limitations, apparently regarding it as
a synonym for the Gasteromycetes of Fries. Link's usage passed un-
challenged for over a quarter of a century. The slime molds were
set apart by themselves; they were fungi without question and, of
course, plants.

In 1858 de Bary published the first of his noteworthy studies upon
the Myxomycetes, based upon careful observation of their life cycles
and particularly upon the transition between the plasmodial and
fruiting stages. These studies were greatly amplified in 1859 and 1864.
As a result of his investigations de Bary concluded that the relation-
ships of the slime molds were with the amoeboid protozoa rather than
with the fungi, and to emphasize this viewpoint, proposed the name
Mycetozoa — fungous animals.

In 1884 he modified the group so as to include not only the Myxomy-
cetes of Wallroth, but the Acrasieae of van Tieghem. Of this, more
later. De Bary's name for the group has, with varying limitations,
been since adopted by many distinguished authorities, including
Rostafinski, Saville Kent, Zopf, the Listers and Lankester.

Whatever the position of the slime molds among living organisms
may finally be determined to be, their actual study has been left
almost entirely to the botanists, and particularly to the mycologists.
By vote of the international botanical congresses of Vienna (1905),
Brussels (1910), and Cambridge (1930), the nomenclature of the group
is fixed as beginning with Linnaeus' Species plantarum of 1753. Linnaeus,
to be sure, knew little about the fungi or slime molds, and apparently
cared less. Nevertheless, the fixing of this date permits taking into
account the work of a number of active students of the group dating
from the closing years of the 18th century. Chief among these is
perhaps Bulliard, in whose extensive work "Histoire des Champignons
de la France" (1791) may be found a number of recognizable descrip-
tions and illustrations of slime molds, unexcelled up to that time.
Noteworthy references to certain species were published still earlier
between 1753 and 1791 by Gleditsch (1753), Schaeffer (1762-1774),
Miiller (1777), Batsch (1783-1789), Leers (1789) and others. Since
that time a host of students has given more or less attention to the
group, of whom the outstanding names up to the time of Rostafinski
are Hoffmann, Schrader, Sowerby, Persoon, Fries, Ehrenberg, Link,
Fuckel, Schweinitz, Berkeley, Curtis.

INTRODUCTION 3

The greatest taxonomic advance since Fries is embodied in the
monographic treatment of Rostafinski, whose "Versuch" of 1873 was
followed by the monograph of 1875 and its supplement of 1876.
Rostafinski, a pupil of de Bary, followed that student's example of
making intensive use of the microscope, at that time, of course,
greatly improved over the crude instruments at the command of the
earlier workers, although much inferior to modern apochromatic and
immersion lenses. The monograph and supplement, written in Polish,
were largely inaccessible to students in other countries, but were made
available to English-speaking workers to a considerable extent by
the works of Cooke. In 1892 Massee published his monograph, based
on Rostafinski, but departing in many particulars from his treatment,
and greatly increasing the number of recognized species, not infre-
quently on an insufficient basis. Two years later appeared the first
edition of the standard English monograph, A. Lister's "Mycetozoa,"
revised in 1911 and again in 1925 by his daughter, Miss G. Lister.
The illustrations in this work, many of them in natural colors in the
later editions, have never been surpassed in comprehensiveness and in
general accuracy, and it is not surprising that European treatments in
other languages have largely been modelled upon this excellent work.

In North America the first extensive collections and reports were
made by Schweinitz (1822; 1832). Later active collectors were Curtis,
Ravenel, Ellis, Peck, Farlow, Morgan, Rex, Wingate, Thaxter, Bethel,
Sturgis and Bilgram. Cooke, in 1877, published the first general ac-
count of the slime molds of the United States, followed by that of
Morgan (1893-1895). The account of the slime molds of eastern Iowa
(1892) and of Nicaragua (1893) by Macbride, preceded the first edition
of his North American Slime-Moulds (1899). The greatly enlarged
and emended second edition of this work (1922) is the basis for the
present study.

As already mentioned, there has been no general agreement as to the
limits of the Myxomycetes, nor is there one at present. A number of
groups of doubtful position have been regarded as related to the slime
molds by some authors, but excluded by others. De Bary, as already
noted, included the Acrasieas. This curious group of organisms, first
studied by van Tieghem, resembles the Myxomycetes in the possession
of a naked amoeboid stage, but its members possess neither swarm-
spores nor a true Plasmodium. Just before fructification the amoebae
become aggregated but do not lose their individual identity; can, in
fact, readily be shaken apart in water. Their resemblance to the
Myxomycetes seems to be superficial only, and most recent workers
have been inclined to doubt their close relationship.

4 THE MYXOMYCETES

The Plasmodiophoracese includes Plasmodiophora and several other
genera parasitic on vascular plants. They show several points of
resemblance to the Myxomycetes, especially in the character of the
zoospore with its apical flagellum. On the other hand they entirely
lack the secreted sporangial wall and the capillitial threads found in
most of the true slime molds and have been held to possess a distinctive
type of nuclear division. Schroeter (1886, p. 133) erected the order
Phytomyxini to contain them and his classification has been exten-
sively followed. The tendency among recent authors, e. g., Gaumann
(1926), Gaumann and Dodge (1928) and Fitzpatrick (1930) has been
to include them among the lower Phycomycetes.

The Labyrinthuleae is a curious group of organisms of uncertain
position, containing two genera and a small number of species, and
characterized by an assimilative phase known as a net Plasmodium,
which is thought by Zopf (1885) to be intermediate in character be-
tween the aggregate amoeboid mass of the Acrasieae, and the Plasmo-
dium of the true slime molds. Much more study is required before
these organisms can be placed in a satisfactory relationship with other
forms, but at the present time the evidence does not warrant including
them in the Myxomycetes.

Jahn, in one of the most recent general treatments of the Myxomy-
cetes (1928), excludes the Acrasieae and Plasmodiophoraceae from the
group, but includes the order Hydromyxales, a small group of aquatic
organisms, of which Vampyrella is the best known genus. The order is
divided into two families. In the less specialized, the Plakopodaceae,
there is no suggestion of a plasmodium, but it is included because of its
probable relationship with the other family, the Vampyrellaceae. The
latter possesses a multinucleate, naked assimilative phase which Jahn
regards as a plasmodium similar to that of the slime molds. The
manner of life and the reproduction are so different from those of the
slime molds that it seems best to exclude this group also, pending fuller
information.

This leaves, then, two major divisions in the Myxomycetes, the
Exosporeas and the Myxogastres or Endosporeae. The structure and
life-histories of these two groups, here ranked as subclasses, is suffi-
ciently different to make it desirable that they be considered separately.

1. Exosporece. Represented by a single genus, Ceratiomyxa. Several
species have been described, but the fructification is so variable that it
seems better to include them all as varieties and forms of a single
species, C. fruticulosa. This is extremely common, found on decaying
wood throughout the greater part of the world. The plasmodium is at
first colorless, then white, or occasionally pinkish or bluish, and lives

INTRODUCTION 5

within the wood; upon what it feeds, or how it grows, little is known,
although it has recently been demonstrated that it may feed to some
extent, at least, upon bacteria. When ready to fruit the Plasmodium
appears at the surface and proceeds to form erect sporophores. These
may be poroid or clavate, or dendroid and elaborately branched, with
all intermediate conditions. While the sporophores are in process of
formation, according to Jahn the bulk of the nuclei undergo reduction
division, the rest degenerating, as in the Myxogastres. When the
sporophores are mature, the surface becomes marked off into poly-
hedral, uninucleate protospores, each of which becomes elevated upon
a slender stalk and is transformed at the tip into a smooth-walled,
elliptical spore. Within the spore, the nucleus divides twice mitoti-
cally, so that at maturity the spores are 4-nucleate. Upon germination
the contents of the spore emerge as an amoeboid body which may pro-
duce short pseudopodia. The nuclei shortly divide again and the whole
mass becomes separated into eight uninucleate portions each of which
develops a flagellum and swims off as a pyriform swarm-cell. The
nuclei of the younger sporophores seem to be diploid, those of the
swarm-cells haploid. According to Jahn (1908), fusion occurs at the
time the plasmodium emerges from the wood. Olive (1907) claims that
fusion occurs just before the formation of the protospores and regards
the first two divisions in the spore as constituting the reduction divi-
sions. H. C. Gilbert has recently demonstrated, however, that fusion
occurs between the swarm-cells, and supports Olive's view as to the
place of reduction division.

2. Myxogastres. This subclass includes all of the slime molds except
Ceratiomyxa, — some four hundred species. The fructification is char-
acterized by a wall which surrounds the spores and other internal
structures. The wall may be thick or thin and relatively permanent or
quickly fugacious, but it is always present. The spores are uninucleate
when formed normally, but the nucleus may divide before germination.
They are small, more often under than over 10 \x in diameter, and en-
closed in a cellulose membrane. This is rarely smooth, usually finely or
coarsely echinulate or verrucose, or reticulate. The spore markings are
rather constant in a given species and hence serve as useful taxonomic
characters. In spite of their small size, the spores are extremely tena-
cious of life. E. C. Smith, who has investigated this phase of their
life-history intensively, reports germination of the spores of a number
of species, from collections left in the herbarium for from ten to thirty-
two years (1929) ; later, in correspondence, he has extended the upper
limit to forty-four years.

Germination of most species takes place fairly readily in tap water or

6 THE MYXOMYCETES

distilled water, but their behavior is often highly erratic, so that the
accounts of different students are not in complete accord either as to
the fact of germination in a given species or as to the time and manner.
Nearly all agree that the spores of Reticularia lycoperdon and Fuligo
septica germinate quickly and easily, as do those of many species of
Physarum. Other forms germinate slowly and with difficulty. Among
the factors which seem to influence germination are the age of the
spores, the circumstances under which they were formed and the
H-ion concentration of the medium. Doubtless others will be added.
At germination the spore wall breaks and from one to four swarm-
cells emerge. Sometimes the protoplasmic contents pass out as a
vesicular mass and then become differentiated into one or more swarm-
cells. The swarm-cell is comma-shaped, with an anterior flagellum
attached by its base to a bell-shaped body adjoining the anterior
nucleus. The posterior end is more or less amoeboid and contains a
large vacuole. The swarm-cell moves in a jerky fashion in a more or
less spiral path, feeding on bacteria and fungus spores, and probably
taking in nutrient materials in solution when such are present. Even-
tually it settles down, loses its flagellum and divides into two similar
cells which develop flagella. This process may continue for some time
but eventually the swarm-cells function as gametes, fusing in pairs.
The zygote thus produced is the first stage of the young plasmodium.
It feeds and grows and the nuclei divide. It may also fuse with other
Plasmodia. Cienkowski (1863), who gave the plasmodium its name,
believed it always arose from the fusion of numerous swarm-cells, but
recent studies throw doubt upon this. Wilson and Cadman (1928)
show that in Reticularia lycoperdon swarm-cells which have failed to
fuse may be incorporated into the zygote, but they serve as food-mate-
rials, the nuclei being destroyed and absorbed with the protoplasm.
This, of course, alters the conception of a plasmodium as Cienkowski
interpreted it and as it has been incorporated in the literature; but the
term is so useful as a designation for the naked, multinucleate, assim-
ilative phase of the slime molds that it seems well to retain it in its
altered sense. There can be no question that large plasmodia fuse.
When grown in culture, a single plasmodium in its progress across the
substratum may break up into two or more separate plasmodia. These
usually meet sooner or later and become completely incorporated
without the least difficulty. It cannot be regarded as proved, however,
that the origin of the plasmodium is always from the fusion of two
gametes. Schiinemann (1930), working with Didymium nigripes and
other species, showed that several swarm-cells may unite to form a
Plasmodium with haploid nuclei and that nuclear fusion occurred in

INTRODUCTION 7

the young plasmodium, thus confirming in part Cienkowski's observa-
tions.

At any time after germination of the spores, unfavorable conditions
may cause the swarm-cells or myxamcebae to cease their activities.
Each becomes surrounded by a hyaline wall, forming a microcyst,
which remains dormant until favorable conditions again appear, when
it gives rise to a swarm-cell.

The determination of the manner of the multiplication of the
nuclei in the plasmodium has offered certain difficulties. Many years
ago J. J. Lister (A. Lister, 1893) demonstrated mitotic division of the
nuclei in Badhamia utricularis and since that time there have been
occasional observations in other species. So many attempts to secure
this stage failed, however, that there arose a widespread belief that
many of the divisions must be amitotic. Both Schunemann and
Howard (1932) have recently shown that division may be completed
within twenty minutes or half an hour and that it occurs nearly
simultaneously throughout a large plasmodium. This demonstration
explains why so many attempts to find it have failed. There is no
reason to doubt that indirect nuclear division is the rule and that
direct division rarely, if ever, occurs.

In a number of cases the food of the plasmodium is known to con-
sist of solid material. As early as 1877, A. Lister observed that the
Plasmodium of Badhamia utricularis was parasitic upon a species of
Corticium, publishing his notes upon the behavior of this species and
of Brefeldia maxima in 1888. Physarum polycephalum has been repeat-
edly grown upon the hymenium of agarics in the laboratories of the
University of Iowa since the 90's. A number of other instances of
proved or suspected parasitism upon the hyphae and hymenia of the
higher fungi have since accumulated. These are summarized by
Howard and Currie (1932) who add extensively to the number, list
fifteen species known to be parasitic, and report extensive experiments
using a wide range of Hymenomycetes as substrata. Several species
have been grown in pure culture; among others, Didymium difforme
(Skupienski, 1926, 1927, 1928) and Didymium nigripes (Cayley, 1929).
F. A. Gilbert (1928) has shown that the swarm-spores of Dictydia-
ihalium plumbeum may be nourished not only by soluble material but
by bacteria and the spores of fungi. Watanabe (1932) experimented
with seventeen species of slime molds and sixteen species of bacteria
and found that all the slime molds could utilize bacteria to some
extent as food but that there was great variation in the range of
bacteria acceptable to different species, and in the reactions of the
slime molds to them.

8 THE MYXOMYCETES

To speak of such organisms as saprobes is obviously inaccurate.
In many species the plasmodium spends its life within the tissues of
decaying wood, probably feeding partly on bacteria, fungous hyphae
and spores and perhaps protozoa; in a considerable number of species
the plasmodium may be found on the surface of decaying leaves or
fragments of woody debris. Very early in its development, the plas-
modium begins to manifest its tendency to become divided into vein-
like branches which redivide and then become reunited to form a
more or less fan-shaped network with a continuous layer of protoplasm
at the advancing margin. The structure of the plasmodium is not
uniform; there is an outer, hyaline region surrounding the inner gran-
ular portion and it is in the latter that the nuclei are found, so that
the outer portion seems to perform essentially the functions of the wall
of the thallus in one of the larger Phycomycetes. The protoplasm of
the interior exhibits a series of pulsating movements, flowing first in
one direction, then in the other, but the movement is always a little
stronger in the direction in which the plasmodium as a whole is mov-
ing. As it progresses over the substratum a shell of waste material
and secreted matter is left, marking the position of the principal veins
and suggesting collapsed hyphae.

Because of the ease of securing relatively large amounts of proto-
plasm free from cell-walls and other skeletal material, the plasmodia
of slime molds have often suggested themselves as favorable material
for the chemical study of protoplasm. Kiesel (1930) points out that
the auxiliary and associated materials ordinarily used in other cells
for accessory purposes are present in plasmodia; hence the assumption
that plasmodia exhibit more pure protoplasm than other cells or proto-
plasmic masses is without adequate basis. Because, however, the
associated materials are incorporated in the general mass, the colloidal
elements of the protoplasm are exposed and easily accessible.

In color, the plasmodia vary from hyaline or white through yellow,
orange, red, violet, blue, green and brown. Pallid grays, yellows and
browns are perhaps the commonest colors. While the color of the
Plasmodium is fairly constant for a given species, it is subject to con-
siderable variation, even in the same plasmodium, upon different
substrata and at different stages of development. Hence, while plas-
modial color is of some value as a taxonomic criterion, it must be used
with caution. Solacolu (1932) has shown that the myxomycete pig-
ments have the properties of anthracenes, which are of common
occurrence in fungi as in plants, but of doubtful occurrence in animals.

The changes through which the plasmodium passes in becoming
transformed into a fructification have been followed in a number of

INTRODUCTION 9

species, and while the details vary there is much that all the species
studied have in common. Bulliard, as far back as 1791, noted and
illustrated certain external features of this process but it was not until
1859 that de Bary attempted to trace the details in the case of Fuligo
septica. Recent careful studies combining morphological and cy to-
logical detail are those on Reticularia lycoperdon and Physarum poly-
cephalum already cited. The process varies somewhat, depending
upon the nature of the fructification, whether plasmodiocarpous or
sporangiate.

An athalium may be defined as a slime mold fructification in
which all or a considerable part of a given Plasmodium is involved,
and in which differentiation has not proceeded to the delimitation
of separate sporangia. It must, therefore, be distinguished from a
pseudo-aethalium, as found in species of Tubifera and species such as
Stemonitis confluens, where the sporangia are delimited but borne in
compact and more or less attached groups.

The plasmodiocarp may tentatively be regarded as less primitive
than the aethalium because it merges into the sporangiate type of
fructification. Further investigation may show, however, that it is
more primitive, and that both the sporangiate and aethalioid types
represent modifications of the plasmodiocarpous. In the typical
manifestations of the plasmodiocarp, as illustrated, e. g., by Physarum
serpula or Hemitrichia serpula, the protoplasm is aggregated into a
few of the larger veins as they rest upon the surface of the substratum,
and there becomes transformed into a fructification which has the
interior structure of a sporangium, but which retains the netted form
and outline of the Plasmodium. In species with distinct sporangia the
Plasmodium often assumes such a netted form before breaking up
into the primordia of the sporangia. The plasmodiocarp tends to
become shorter and less branched and thus merges by gradual degrees
through linear and pulvinate fructifications into the sporangiate

fc yp e - . . c

The sporangium is typically an erect fructification of definite form
and structure for a given species, each sporangium representing only
a small part of the protoplasm of a given plasmodium, hence sporangia
tend to be grouped in clusters or extensive masses, the entire group
representing the area occupied by the fruiting plasmodium. Dis-
carded remnants of the plasmodium usually remain at the base of the
sporangia, forming the hypothallus; sometimes in definite sheets, as
in the stemonites, less definite in the lower layer of plasmodiocarpous
or aethalioid fructifications. In Diachea leuco podia it appears as the
arrested network of the fruiting plasmodium. In other species, repre-

10 THE MYXOMYCETES

sen ting various groups, it shrinks to a small disk-like base at the
foot of each sporangium. Only rarely is it entirely absent. The
sporangia may be sessile or stalked, and the stalk, when present, may
be solid, and then usually horny or calcareous, or hollow, when it is
commonly filled with waste material or spore-like cells. Not infre-
quently the stalk is prolonged into the interior of the sporangium as
a conical, cylindrical or swollen columella. The columella is particu-
larly well developed in Stemonitis, Comatricha, Lamproderma and
related genera.

The essential parts of the sporangium are the enclosing wall and
the mass of spores. In addition a capillitium is often present, composed
of netted tubes or thread-like processes. The sporangium wall is not
cellular in structure but is in the nature of an excretion. In some
species it is relatively constant in thickness and appearance; in others
it is variable, the differences being presumably due to variations in
the external environment during its formation. In most species of
Stemonitis and Comatricha it is exceedingly delicate and disappears
as soon as the sporangium is mature. In Arcyria the upper portion
is broken into flakes by the expanding capillitium and falls away,
leaving only the persistent cup-like base. In the crateriums and in
many of the badhamias, physarums and didymiums it remains for a
long time, while in the didermas it is often well preserved long after
the spores have been discharged.

The capillitium is sometimes completely lacking, as in Licea and
Cribraria. In Badhamia it is in the form of a network of limy tubes;
in Physarum and related genera the lime is aggregated into nodules
which are connected by a network of nearly or quite limeless tubules.
In Stemonitis, Comatricha and Lamproderma the capillitium arises as
branches of the columella. In Hemitrichia and Arcyria it takes the
form of a network of elaborately sculptured tubes, while in Trichia
the threads are like those of Hemitrichia, but shorter and separate.
In Lycogala, Reticularia and Enteridium a true capillitium is lacking
but its place is taken by a pseudocapillitium composed of coarse
tubes or frayed or perforated plates. The distinction is based on the
method of formation, the true capillitium being formed of materials
laid down by intra-protoplasmic secretion on the walls of vacuoles or
tubular invaginations, while the pseudocapillitium is the direct product
of the degeneration of a portion of the protoplasm itself. Since the
development of only a comparatively small number of species has
been studied, the mode of formation of the capillitium must in most
instances be inferred, but the differences between the two structures
are such as to lead to little uncertainty in practice.

INTRODUCTION 11

The Plasmodium does not always proceed to fructification without
interruption. Under the influence of dryness, cold, lack of food-
materials and probably other unfavorable conditions it may become
transformed into a hard, horny resting stage, or sclerotium. Within
the sclerotium, the protoplasm is aggregated in masses containing a
number of nuclei. In such condition the plasmodium may remain
dormant for a considerable length of time, presumably over winter
in most species of temperate climates, and in some cases at least for
two or three years, resuming activity with the advent of favorable
conditions.

The Myxomycetes are of no direct economic importance. The ex-
clusion of the Plasmodiophoraceas removes the only group of plant
parasites. From time to time certain species appear on economic
plants — Physarum gyrosum on sweet potato vines, Physarum cinereum
on strawberry plants and lawn grass — but while they may alarm the
proprietor, they do no harm and soon disappear. A recent study by
Thorn and Raper (1930) shows that myxamcebae and plasmodia are
constantly present in the upper layers of soil and in the decaying
vegetable debris at the surface, and these authors note that members
of this group should be considered in studying soil microorganisms.
Active as they are, their role should be investigated, but nothing defi-
nite can be said to be known of it at present.

II. Collection and Care of Specimens

On this subject a word may here be appropriate. Throughout the
world, specimens may be gathered at the proper season in almost any
locality. Beginning with the latter part of May or first of June, in the
northern United States, plasmodia are to be found everywhere on
piles of organic refuse: in the woods, especially about fallen rotting
logs, undisturbed piles of leaves, beds of moss, stumps, by the seeping
edge of melting snow on mountain sides, by sedgy drain or swamp, nor
less in the open field where piles of straw or herbaceous matter of any
sort sink in undisturbed decay. Within fifty years tree-planting in all
the prairie states has greatly extended the range of many more defi-
nitely woodland species, so that the species of Stemonitis, for instance,
are common in the groves on farms far into Nebraska and Dakota. In
any locality the plasmodia pass rapidly to fruit, but not infrequently a
Plasmodium in June will be succeeded in the same place by others of
the same species, until the cold of approaching winter checks all vital
phenomena. The process of fruiting should be watched as far as pos-
sible, and for the herbarium material, allowed to pass to perfection in
the field.

12 THE MYXOMYCETES

Specimens collected should be placed immediately in boxes in such
a way as to suffer no injury in transport; beautiful material is often
ruined by lack of care on the part of the collector. Once at the herba-
rium, specimens may be mounted by gluing the supporting material to
the bottom of a small box. Boxes of uniform size and depth may be
secured for the purpose. Some collectors prefer to fasten the specimen
to a stiff paper, of a size to be pressed into the box snugly, but which
may be removed at pleasure. Every care must in any case be taken to
exclude insects. Against such depredators occasional baking of the
boxes on the steam radiator in winter is found to be an efficient remedy,
or paradichlorobenzene may be sprinkled in the boxes or herbarium
cases two or three times a year. In the United States National Herba-
rium specimens are mounted on the inside of the cover of boxes
1% X 4 X % inches, the label and the specimen thus being in-
separable. The shallow cover permits ready examination of the mate-
rial with lens or binocular microscope. Such boxes fit snugly in a shal-
low box the size of an herbarium sheet, five of which fit easily into a
standard herbarium shelf. This method, while somewhat wasteful
of space in the case of very small collections, is admirably suited to
the great majority of collections, and permits their riling in strict order.
It has been adopted for the bulk of the collections in the herbarium of
the State University of Iowa. This collection, which has served as the
basis for the present work, contains, in addition to the accumulations
of many years by the authors and their colleagues and associates, the
invaluable Morgan and Wingate collections. Included also are note-
worthy gatherings by Ellis, Farlow, Shimek, Rex, Bilgram, Hagelstein,
Harvey, Bethel, H. C. Gilbert and O. A. Plunkett in America, and
Sydow, Japp, Brandza and Meylan in Europe. An interesting series of
duplicates of the collections of O. F. Cook from Liberia, secured by
exchange with the United States National Herbarium, is also included.
The study of this material has been checked by examination of that in
other institutions, particularly the splendid collection in the United
States National Herbarium. Mr. Lister and Miss Lister have courte-
ously given portions of certain critical or doubtful species for compari-
son.

For simple microscopic examination it will be found convenient
first to wet the material with alcohol on the slide, then with a weak
solution of potassium hydroxide (2-3%) to cause the spores and other
structures to assume proper plumpness. A little glycerine may be
added or run under the cover if it is desired to preserve the material
for further or prolonged study. For permanent mounting nothing is
better than glycerine jelly in most cases. As a preparation the material

INTRODUCTION 13

may be placed on a cover-slip in Hantsch's fluid or Amann's medium *
and protected from dust until the volatile constituents have evapo-
rated. A smaller cover-slip may then be placed over the specimen,
using a minute drop of glycerine jelly, and the whole inverted on a slide
over Canada balsam, using the method described by W. W. Diehl,
thus providing a permanent mount suitable for examination under oil
immersion; or the material may be mounted directly on a slide in
glycerine jelly, and ringed with any good microscopic cement. For
nearly all species the best mounts are those which are held in a satu-
rated atmosphere for a few hours and then mounted in water. When
care is taken that the spores of such specimens are not permitted to
swell, as they do previous to germination, they often afford the most
favorable mounts for the determination of spore markings.

Careful comparison of spores from fructifications kept in a saturated
atmosphere and mounted in water, with those mounted in weak po-
tassium hydroxide shows that there is no appreciable difference be-
tween the measurements made of spores mounted in these two ways,
and since the KOH is much more rapid, it is ordinarily used. In the case
of some genera, e. g., Cribraria, Dictydium and many of the Trichiales,
the addition of the alkali produces a marked color change. This may
sometimes be avoided by substituting lactic acid. Many fructifications
contain large spore-like bodies, often somewhat irregular in shape,
which are the result of failure of the protoplasm to proceed to complete
division. In measuring spores, these bodies must be excluded. If the
spores are on the whole uniform in size, an average of ten measure-
ments may be taken as representative of the collection. Where the
spores are more variable, a larger number of measurements must be
made.

In the matter of nomenclature, the attempt has been made to adhere
to the rules of the International Botanical Code. In certain instances,
where the rules permit some degree of latitude, the authors have pre-
ferred to err on the side of strictness rather than laxity. It is believed
that in the long run this will be more likely to lead to nomenclatorial
stabilization than the greater freedom permitted, but scarcely en-
couraged, by the rules.

♦Hantsch's fluid:

Alcohol 90% three parts

Water two parts

Glycerine ... . . . • • • . . one part

Amann's medium:

Phenol 20gms.

Lactic acid .......... 20 gms.

Glycerine 40 ml.

Water 20ml.

14 THE MYXOMYCETES

Decision as to the limits of species and genera must necessarily be a
matter of personal judgment, and this is perhaps more apparent in the
slime molds, because of their obvious responsiveness to environmental
conditions while the fructifications are forming, than in most other
groups. We have felt justified in applying a distinctive specific name
to any form which shows reasonable constancy under varying condi-
tions, even though occasional intermediate forms may appear. The
multiplication of varieties has nearly if not quite reached the satura-
tion point. Many of the varieties listed in the literature are obviously
merely growth forms; some are doubtless autonomous species. If
the latter, they will eventually be recognized as such; if the former, it
would seem better to modify the diagnosis of the species to accommo-
date them, rather than to multiply names.

The space devoted to synonymy is extensive. It is unfortunate that
this should be so, but at present it seems to be necessary. Many
synonyms are listed on the authority of earlier students, particularly
Rostafinski, and in view of the scanty and inadequate descriptions
given in many of the earlier works, many must be regarded as doubtful.
Where possible, however, the original descriptions have been consulted,
and the attempt has been made to judge their value impartially. We
have included either in the synonymy or the appendix many published
names which have been applied to slime molds, even certain names not
validly published but which have appeared in the literature. If they do
nothing else, such compilations help to prevent the publication of
invalid names, and, in case of doubt, send the student to original
sources for verification of conclusions.

THE MYXOMYCETES

Subclass EXOSPORE^ RosL

Versuch2. 1873.

Fructification composed of stalk-like, membranous, columnar, sim-
ple or branching sporophores or sometimes pore-like folds. Spores
white, stalked, borne superficially on the surface of the sporophores.
A single genus:

Ceratiomyxa Schroeter

in Engler & Prantl, Die nat. Pflanzenfam. 1 (i) : 16. 1889.
Ceratium Alb. & Schw., Consp. Fung. 358. 1805, non Shrank 1793.

Sporangia none; spores superficial, colorless, on erect papillae or
branches or on the inside of minute depressions or pits, each spore
surmounting a delicate pedicel or stalk. Mature spore 4-nucleate, on
germination giving rise to a rounded amoeboid body, which, after
another nuclear division becomes transformed into eight flagellated
swarm-cells. Plasmodium inhabiting sodden wood, emerging to form
the fructification.

The spores, in manner of formation and of germination, differ widely
from those of the other genera, with which their homologies seem ob-
scure. It has been suggested that the pedicels represent incipient
stipes; the spores primitive or simplified sporangia.

Several species have been described but they all seem to merge
into each other and thus to be variants of a single species, too incon-
stant to deserve even varietal recognition for the most part, although
in deference to custom the varieties are here listed.

Ceratiomyxa fruticulosa {Muell.) Macbr.

N. A. Slime-Moulds 18. 1899.
PL I, Figs. 1, 2, 3, 4, 5.

1777. Byssus fruticulosus Muell., Fl. Dan. 6 : 718.

1778. Tremella hydnoidea Jacquin, Misc. 1 : 145.
1783. Clavaria puccinia Batsch, Elench. Fung. 139.

1791. Clavaria byssoides Bull, Champ. France 209, pi. 415, fig. 2.
1791. Puccinia byssoides (Bull.) Gmelin, Syst. Naturae 2 : 1462.

15

16 THE MYXOMYCETES

1794. Isaria mucida Pers., Roemer N. Mag. Bot. 1 : 121.

1805. Ceratium hydnoides (Jacq.) Alb. & Schw., Consp. Fung. 358.

1805. Ceratium pyxidatum Alb. & Schw., Consp. Fung. 359.

1879. Ceratium fuscum Cooke, Grev. 8 : 60.

1879. Ceratium roseum Cooke, Grev. 8 : 60.

1880. Ceratium sphtzt videum Kalch. & Cooke, Grev. 9 : 22.

1885. Ceratium mucidum (Pers.) Schroet., Krypt. Fl. Schles. 3 (1) : 101.
1889. Ceratiomyxa mucida (Pers.) Schroet., in Engler & Prantl, Die nat. Pflanz.
1 (i) : 16.

Plasmodium usually colorless, sometimes yellow, rosaceous, green-
ish or bluish; sporophores white or occasionally yellowish, pinkish or
bluish, forming on the substratum mold-like patches composed of the
simple or branched sporiferous pillars, 1-10 mm. tall, sometimes
more; spores borne externally on slender individual stalks, hyaline,
very variable in shape and size but commonly oval or elliptical,
8-14 X 6-8 fi.

World-wide in distribution and extremely common, occurring
especially after warm showers and in sultry weather. The spores
vary from spherical to oval, elliptical and occasionally to pyriform
and somewhat allantoid. Some fructifications bear spherical or short
elliptical spores only 7-8 fx in diameter, but great variation in
both shape and size may be found among the spores borne on a
single stalk. Some of these variations are doubtless due to different
degrees of maturity.

Micheli's figure of 1729 is as good as that of Mueller. The latter
referred the species to the Linnaean genus Byssus, which included
algae as well as fungi. The same thing is true of Tremella, which is
now definitely restricted to the Heterobasidiomycetes. All the other
genera with which the genus has been associated, down to Ceratiomyxa,
are now otherwise applied. Mueller's specific name seems to have
undisputed priority.

The extreme variability of the species has led to the proposal of a
number of varieties as well as specific segregates. These all merge
into one another, but the following forms seem for the present to merit
recognition as varieties.

Var. arbuscula Berk. & Br. (Ceratium arbuscula Berk. & Br., Jour.
Linn. Soc. 14 : 97, 1873). This is a form in which each sporophore
has a single short stalk which becomes profusely branched in tree-like
fashion.

Var. filiforme Berk. & Br. (Ceratium filiforme Berk. & Br., Jour.
Linn. Soc. 14 : 97, 1873). This variety is characterized by very long,
slender sporophores, sometimes unbranched for 3-4 mm. then branch-
ing profusely in a tuft at the top, the branches of the neighboring

MYXOGASTRES 17

sporophores interlacing to form a dense mat concealing the substratum
and covering an area several centimeters square. Most common in
the tropics of both hemispheres.

Var. porioides Alb. & Schw. {Ceratium porioides Alb. & Schw.,
Consp. Fung. 359, 1805; Ceratiomyxa porioides (Alb. & Schw.) Schroet.
in Engler & Prantl 1 (i) : 16). Sporophores confluent, porose; pores
ample, angular, at length radiate-dentate. Ceratium crustosum Berk.
& Curt., Grev. 3 : 62, 1874, is merely a crustose form of this variety.
The var. porioides has frequently been regarded as a distinct species
and it ordinarily appears to be so, but cases occur in which it and the
typical form arise together from the same Plasmodium, hence the
attribution of a yellow Plasmodium to this variety cannot be regarded
as significant. Widespread and fairly common, but not so frequent
as the typical form.

Var. ctzsia Jahn {Ceratiomyxa ccesia Jahn, Ber. Deutsch. Bot. Ges.
36 : 660, 1919) is similar to var. porioides, but tinged with green, and
developing from a bright blue-green plasmodium. It has been reported
only from Germany.

Ceratiomyxa freyana Meylan (Bull. Soc. Vaud. Sc. Nat. 56 : 65,
1925) is described as arising from a bright yellowish green or citron
yellow plasmodium and as occurring in scattered small patches. In
other respects it seems not to differ from typical C. fruticulosa and
judging by the description is doubtfully distinct. It has been reported
from Switzerland and Rumania.

Subclass MYXOGASTRES Fries ex Macbr.

1829. Suborder Myxogastres Fries, Syst. Myc. 3 : 67.

1833. Suborder Myxomycetes Link, Handb. der Gew. 3 : 405.

1858. Class Mycetozoa de Bary, Bot. Zeitung 16 : 369, in part.

1889. Class Myxogasteres Schroet., in Engler & Prantl 1 (i) : 8, in part.

The slime molds included in this subclass are characterized by
abundant, minute, unicellular spores, enclosed in more or less per-
fectly denned sporangia and often accompanied by peculiar thread-like
or tube-like structures, free or variously attached and joined, forming
the capillitium. The spores on germination give rise either to swarm-
cells, or to amcebulae, which directly or by division give rise to swarm-
cells. After one or more divisions the swarm-cells function as gam-
etes, conjugating in pairs, the resultant amoeboid zygotes constituting
the young plasmodia. These feed voraciously, the nuclei dividing as
they enlarge. They also probably fuse with each other, and, when the
proper conditions arise, become transformed into the fructifications
typical of the several species. /CS^

18 THE MYXOMYCETES

KEY TO ORDERS OF THE MYXOGASTRES

a. Spore mass black or deep violaceous, rarely ferruginous or pallid; capil-
litium always present b

a. Spore mass usually brown or yellow, sometimes purplish or rosy, very rarely

blackish brown ; capillitium present or absent c

b. Peridium or capillitium, or both, calcareous Order PHYSARALES

b. Peridium and capillitium usually limeless; lime
if present restricted to hypothallus, stipe and
columella Order STEMONITALES

c. True capillitium none or scanty (except in genus
Alwisia); pseudocapillitium often present, of tubules
or perforated plates which sometimes fray out into
threads; spores pallid, brown or purplish Order LICEALES

c. Capillitium thread-like, more or less distinctly sculp-
tured, parietal or free; spores pallid or yellow Order TRICHIALES

The sequence is intended to suggest that the presence of lime indi-
cates less complete specialization and that the elimination of lime by
the Plasmodium at the outset, before fructification, is indicative of
higher rank. The circumstance that the excreted lime may sometimes
serve a protective purpose does not vitiate the general principle.
The differentiation reaches a climax in the sculptured capillitium of
the trichias.

Order PHYSARALES

Spores violaceous black in mass; violaceous or violaceous brown by
transmitted light. Capillitium typically delicate and thread-like,
sometimes charged with lime, in one genus tubular and calcareous
throughout. Peridium simple or double, usually limy.

The presence of calcareous deposits, either in the capillitium or the
peridium or the stalk, often in all three, is the chief diagnostic char-
acter of the order. Elsewhere similar deposits occur in the genus
Diachea only, in this treatment placed in the Stemonitales, but by
Lister and others placed in the Physaraceas, and clearly intermediate
in its relationships.

Two families:

KEY TO FAMILDZS OF PHYSARALES

Capillitium more or less calcareous, usually reticulate or anastomos-
ing in intricate fashion; calcareous deposits often affecting entire
fructification Physaracejs

Capillitium non-calcareous, usually less intricate; calcareous de-
posits affecting the peridium only, or the peridium and the
stipe Dedymiace^

PHYSARACE.E 19

Family PHYSARACE^E

Capillitium more or less calcareous, the lime typically in the form
of nodules connected by tubular hyaline threads, sometimes calcareous
throughout; peridium usually more or less incrusted, and often the
stipe. Spores violaceous black in mass; purple or lilaceous brown by
transmitted light.

KEY TO THE GENERA OF THE PHYSARACEjE

a. Fructification aethalioid 1. Fuligo

a. Fructification plasmodiocarpous or of separate sporangia b

b. Capillitium composed of a network of tubules, calcareous

throughout 2. Badhamia

b. Capillitium of hyaline threads connecting nodules of lime c

c. Peridium obviously calcareous d

c. Peridium appearing nearly limeless h

d. Fructification long-cylindrical, branching, pendent 3. Erionema

d. Fructification plasmodiocarpous and appressed to sub-
stratum, or of sessile or stalked sporangia e

e. Dehiscence circumscissile or by a definite lid 5. Craterium

e. Dehiscence irregular ■ /

/. Fructification plasmodiocarpous or of distinct sporangia,
the latter subglobose, laterally appressed or gyrose, but

the peridium not introverted 4. Physarum

f. Fructification rarely plasmodiocarpous, usually of stalked

sporangia, with the peridium more or less introverted g

g. Sporangia saucer-shaped, fragile; dehiscence irregular 6. Trichamphora

g. Sporangia thimble-shaped, rarely plasmodiocarpous; dehis-
cence by petal-like lobes 7. Physarella

h. Plasmodiocarpous; capillitium with free, hooked branches 8. Cienkowskia
h. Sporangia distinct, ovoid; peridium shining 9. Leocarpus

1. Fuligo Holier emend. Pers.

Syn. Meth. Fung. 159. 1801.

1768. Fuligo Haller, Hist. Stirp. Helv. 3 : 110, in part.
1809. Mhalium Link, Mag. Ges. Nat. Fr. Berl. 3 : 42.

Fructification aethalioid, occasionally subplasmodiocarpous, forming
a pulvinate or less commonly a subglobose mass composed of inter-
woven and poorly defined tubes, each with a calcareous crust; the
outer layer sterile, usually calcareous, forming a fragile crust or cortex,
sometimes nearly or quite wanting; the basal layer a membranous
hypothallus, the intermediate portion containing the spores and cap-
illitium and the limy tube walls; capillitium of hyaline, thread-like
tubules connecting lime-knots, as in Physarum, often rather scanty.

20 THE MYXOMYCETES

Haller seems to have been the first to recognize the genus. Persoon
defined it more closely and illustrated it. Link merely translated the
name into Greek and in this was followed by Fries.

The structure of the central sporiferous region is difficult to inter-
pret. It is commonly regarded as composed of tortuous, interlaced
sporangia, but it seems more reasonable to regard these bodies as more
in the nature of plasmodiocarps, representing the principal veins of
the Plasmodium which have matured without proceeding to the spo-
rangial stage. The walls of these bodies, whatever their nature, to a
considerable extent take the place of a capillitium and hence form a
pseudocapillitium in addition to the true capillitium formed within
them.

The taxonomy of the genus is likewise perplexing. Are the various
forms simply phases of a single species or to what extent are they
sufficiently constant in their admitted variety to claim specific rank
and separate description? To follow the example of Greville and
recognize in all the literature of two centuries varied descriptions of a
single type — this were perhaps the easier and speedier disposal of
the case. Fries thought so to treat the problem but was unable to keep
faith with his own decision, for he no sooner states the genus mono-
typic then he proceeds to offer four varieties, the same as those recog-
nized by Persoon and others as species. More recent students seem
to find convenience in specific division, thus indicating that to careful
observers all over the world there are differences that may be and
have been recognized again and again. It will be said, was said by
Fries, that these variations are insignificant, "pendent ex aeris consti-
tutione"; but as a matter of fact the several types here described may
be found on the same day in similar habitats, so that evidently some-
thing other than atmospheric environment must determine their final
aspect. However it may be, there are many varying presentations of
Fuligo capable of illustration and description. Some of these forms
we venture to describe, with such annotation as may show something
of present knowledge.

KEY TO THE SPECIES OF FULIGO

a. Spores predominantly elliptical; fructification plasmodiocar-

pous or sethalioid; crust white I. F. cinerea

a. Spores predominantly spherical; fructification aethalioid; cor-
tex various b

b. /Ethalia small, usually 1 cm. or less in diameter 2. F. muscorum

b. y£thalia larger, usually 2 cm. or more in diameter c

c. Spores mostly 6-9 n, always under 10 /z 3. F. septica

c. Spores 1 1 n or larger d

FULIGO 21

d. Cortex thin, fragile, not calcareous, grayish or brownish,

often wanting; spores 11-13 /i, nearly smooth 4. F. intermedia

d. Cortex thick, spongy, calcareous; spores 15 y. or over,

rough-tuberculate 5. F. megaspora

1. Fuligo cinerea (Schw.) Morg.

Jour. Cin. Soc. Nat. Hist. 19 : 33. 1896.
PI. I, Fig. 11.

1832. Enteridium cinereum Schw., Trans. Am. Phil. Soc. II. 4 : 261.

1832. Lachnobolus cinereus Schw., Trans. Am. Phil. Soc. II. 4 : 261.

1875. Badhamia coadnata Rost., Mon. 146.

1876. Physarum ellipsosporum Rost., Mon. App. 10.
1885. jEthaliopsis stercoriformis Zopf, Pilzthiere 150.

. 1887. Fuligo stercoriformis (Zopf) Racib., Hedwigia 26 : 111.
1894. Fuligo ellipsospora (Rost.) Lister, Mycetozoa 67.

Fructification usually more or less plasmodiocarpous, long, widely-
effused, thin, applanate, often reticulate, from a few millimeters to
2-3 centimeters in extent; cortex white, firm, membranous, but rather
thick; capillitium well developed, with large and irregular calcareous
nodules; spores filaceous brown, elliptical, subspherical or spherical,
rather coarsely spinulose, 14-16 X 11-12 ju. Plasmodium milk-white,
watery, changing to cinereous.

In shaded situations on piles of rotting straw or manure, or on de-
tritus in the woods, especially that of bracken. Some of the spores
are nearly or quite spherical but the majority are elliptical. Rostafinski
called it first a badhamia, then a physarum; Zopf founded for it a
new genus yEthaliopsis. Recent students are agreed that it is better
included in Fuligo. Large, gray, pulvinate forms with small spherical
spores are often found in herbaria labelled F. cinerea but usually prove,
on examination, to be F. septica var. Candida.

Not common in eastern North America, but extremely common in
the coniferous forests of the northwest. Occurring also in Europe,
Asia, Africa.

2. Fuligo muscorum Alb. 6 s Schw.

Consp. Fung. 86. 1805.
PI. I, Figs. 9, 10.
1809. Lignidium griseoflavum Link, Mag. Ges. Nat. Fr. Berl. 3 : 24.
1817. Lignidium muscicola Fr., Symb. Gast. 10.
1829. Reticularia muscorum (Alb. & Schw.) Fr., Syst. Myc. 3 : 91.

1875. Physarum gyrosum Rost., Mon. Ill, in part.

1876. Licea ochracea Peck, Rept. N. Y. State Mus. 28 : 55.
1879. Fuligo ochracea Peck, Rept. N. Y. State Mus. 31 : 56.
1879. Fuligo simulans Karst, Bidr. Kann. Finl. Nat. 31 : 108.

1888. Physarum muscorum (A. & S.) Berl., in Saccardo, Syll. Fung. 7 : 346.

22 THE MYXOMYCETES

yEthalia pulvinate or somewhat globoid, irregular, small, usually
1 cm. or less in width; cortex very thin, gray or greenish yellow, bear-
ing scattered deposits of yellow lime nodules; internal walls frequently
not evident; capillitium well developed, the numerous fusiform or
branching calcareous nodes yellow, ochraceous or sometimes nearly
white, connected by rather short hyaline threads; spores violet-brown,
coarsely, somewhat irregularly and not very closely warted, 11-13 /*.
Plasmodium yellow.

The above description is based mainly on material from northern
New York said by Rex to agree with specimens of Fuligo ochracea
Peck in the New York State Museum. The distinctive characters,
aside from the small size, seem to be the dull greenish or gray peridium,
with its scattered deposits of yellow lime and the strongly but sparsely
warted spores.

New York, New England, Ontario; Europe, Ceylon. Reported
from Manchuria by Skvortzow, 1931, but the description given makes
the report doubtful.

3. Fuligo septica (L.) Weber

Wigg. Pr. Fl. Holsat. 112. 1780.
PI. I, Figs. 6, 7, 8.

1763. Mucor septicus Linn., Sp. Plant, ed. 2. No. 1656.

1763. Mucor ovatus Schaeff., Fungi Bav. 132, fig. 192.

1772. Mucor mucilago Scop., Fl. Cam. 2 : 492.

1791. Reticularia carnosa Bull., Champ. 85, pi. 424, fig. 1.

1791. Reticularia hortensis Bull., Champ. 86, pi. 424, fig. 2.

1791. Reticularia lutea Bull., Champ. 87, pi. 380, fig. 1.

1794. Fuligo flava Pers., Roemer N. Mag. Bot. 1 : 88.

1796. Fuligo vapor aria Pers., Obs. Myc. 1 : 92.

1799. Fuligo pallida Pers., Obs. Myc. 2 : 36.

1801. Reticularia ovata (Schaeff.) Wither., Br. PI. ed. 4. 4 : 463.

1801. Reticularia septica (L.) Wither., Br. PL ed. 4. 4 : 463.

1801. Fuligo Iczvis Pers., Syn. Meth. Fung. 160.

1803. Fuligo flavescens Schum., Enum. PI. Saell. 2 : 194.

1809. Mthalium flavum (Pers.) Link, Mag. Ges. Nat. Fr. Berl. 3 : 42.

1825. Fuligo cerebrina Brond., Mem. Soc. Linn. Paris 3 : 74.

1826. Reticularia vaporaria (Pers.) Chev., Fl. Par. 1 : 342.

1826. Fuligo varians Somm., Fl. Lapp. 239.

1827. JEthalium violaceum Spreng., Syst. Veg. 4 : 533.
1829. Mhalium septicum (L.) Fr., Syst. Myc. 3 : 93.
1885. Fuligo tatrica Racib., Hedwigia 24 : 169.

mthalium pulvinate, rarely more or less plasmodiocarpous, varying
in size but usually large, up to 20 cm. or occasionally more in its largest
diameter, and 1-3 cm. thick; color white, yellowish ochraceous, green-

FULIGO 23

ish ochraceous, tawny, brown or deep violet; cortex fragile, calcareous,
thick or almost lacking; capillitium of white, yellow or reddish lime-
knots, connected by hyaline, thread-like tubules, usually well de-
veloped but not infrequently scanty; spore-mass dull black, sooty;
spores purplish brown by transmitted light, mostly spherical, spinu-
lose to nearly smooth, 6-9 n in diameter. The Plasmodium is usually
yellow, but may be white or cream colored.

An extremely variable species, as the extensive synonymy suggests,
and because of its large size and frequent occurrence on spent tan
bark, the typical form has long been familiar and popularly known as
"flowers of tan." It was described under this name in 1727 by Mar-
chant, and again described and illustrated by Micheli in 1729. The
classical studies of de Bary (1859, 1864) give much attention to the
development of this species. World-wide in its distribution, it appears
in its various manifestations in all sorts of exposed situations — logs,
posts, stumps, the bark of living trees, even clods of earth and stones.
The typical form (var. ovata of N. A. Slime-Moulds, ed. 2) is common
on stumps and fallen logs, with us on oak, cotton wood, linden and
maple particularly, but may occur on a variety of substrata, including
bare earth. The fructification is large, yellow, ochraceous or tawny,
with an extremely friable, foamy cortex. The calcareous internal
structure is white. The spores are spherical, nearly smooth and 6-8 n
in diameter. Bulliard figures this phase well on pi. 424, fig. 2, as Reticu-
laria (Fuligo) hortensis. Schaeffer's pi. 132 probably represents the
same thing, as does Bolton's pi. 134. Sowerby's fig. 2 on pi. 399, and
figs. 1 and 2 on Greville's pi. 272 possibly also depict this form. Per-
soon calls this F. vaporaria because it frequents hotbeds and the like,
and believes it to represent the "untuosusflavus" of Linnaeus, although
he thinks Schaeffer's specimens do not.

The following phases seem to be sufficiently constant to warrant
varietal recognition:

Var. Candida Pers. (as F. Candida Pers., Obs. Myc. 1 : 92, 1796).
Plasmodium, sethalium and lime-knots white, giving the whole struc-
ture a grayish white appearance when mature. Plasmodiocarpous
forms of this are likely to be confused with F. cinerea, from which they
may be distinguished by the small, spherical spores. Common.

Var. rufa Pers. (as F. rufa Pers., Roemer N. Mag. Bot. 1 : 88,
1794, = F. carnea Schum., Enum. Plant. Ssell. 2 : 194, 1803; Reticu-
laria carnea (Schum.) Fr., Syst. Myc. 3:91, 1829; Reticularia rufa
(Pers.) Schw., Trans. Am. Phil. Soc. II. 4 : 261, 1832; Mthalium ferrin-
cola Schw., Trans. Am. Phil. Soc. II. 4 : 261, 1832; Mthalium rufum
(Pers.) Wallr., Fl. Crypt. Germ. 11 : 341, 1833; Licea lindheimeri

24 THE MYXOMYCETES

Berk., Grev. 2 : 68, 1873; Tubulina lindheimeri (Berk.) Mass., Mon. 42,
1892). ^thalium usually thick and rather solid; much less flattened
in proportion to its size than the typical form; the cortex is porose
but firm, orange at first, becoming tawny with age, often exhibiting
two distinct layers; the interior grayish; the spores 6-7 /x. Bulliard
figures it well on pi. 380, fig. 1, and Sowerby's fig. 1 on pi. 399 is also
good, as is Greville's fig. 3 on pi. 272, showing the two colors men-
tioned. Not uncommon in the forest, from June to September.
Meylan believes it a valid species.

Var. lams Pers. (as F. lavis). Similar to preceding, but usually
smaller, with a smooth, rusty brown, persistent cortex, which remains
when all the grayish sporiferous mass has been distributed. A forest
form, more apt to be found in the autumn, but appearing in July.

Var. flava Pers. in sense of Morgan. Yellow or yellow-green; wide-
spread, but thin, the cortex yellow but extremely evanescent; the
capillitium yellow throughout. On fallen logs in moist dark woods.
Not common. The spores of most collections of the var. flava tend to
average somewhat larger than those of the other varieties, 8-8.5,
occasionally 9 fx.

Var. violacea Pers. (as F. violacea). Plasmodium dark red or wine
colored; aethalium thin, 5-8 cm. broad; cortex at first dull red and very
soft, at length almost wholly vanishing so that the entire mass becomes
purple-violet, with the upper surface varied with white; capillitium
rather open, of more or less inflated, large irregular nodes joined by
long, slender, transparent filaments. Spores dark violet, minutely
roughened, spherical, about 7.5 fx. Ontario, Tennessee, Wisconsin,
Oregon. Probably widespread, but rarely noticed. Professor Morgan
regarded this as a well-defined species. In our material it seems more
distinct than the other varieties and may prove to be a good species.

4. FULIGO INTERMEDIA Macbf.

N. A. Slime-moulds ed. 2. 30. 1922.
PL I, Fig. 12.

1911. Fuligo cinerea var. ecorticata Lister, Mycetozoa ed. 2. 88.

^thalium 2-3 cm. in greatest diameter, or occasionally somewhat
larger, 0.5-1 cm. thick, covered with a thin, fragile, but not calcareous,
yellowish gray or brownish cortex; spore-mass gray or violaceous to
nearly black, firm, not sooty, the limy plates running through the
mass somewhat calcareous, intricate; capillitium inconspicuous; spores
globose, pale purple, faintly warted, 11-13 fx.

The firm spore-mass and the moderately large spores serve to dis-

BADHAMIA 25

tinguish this from some forms of F. septica to which it bears a close
resemblance; the spherical or slightly irregular but not at all elliptical
spores from F. cinerea.

Apparently western: Iowa, Colorado, Montana, New Mexico, Ari-
zona, Oregon.

5. Fuligo megaspora Sturgis

Colo. Coll. Pub. Sc. Ser. 12 : 443. 1913.
PI. I, Fig. 13.

iEthalia pulvinate, 15-40 cm. in diameter, covered with a thick
spongy incrustation of lime, white, or yellowish toward the base;
interior of convolute tubes, the walls membranous, brittle, charged
throughout with white granules of lime 1.5-2 ix in diameter; capillitium
scanty, of delicate, colorless, anastomosing tubules bearing toward the
center large, white, branching calcareous nodules; spores spherical or
somewhat oval or irregular in outline, dark purplish brown, rough-
tuberculate, the surface markings often united into branching lines
forming an irregular and incomplete reticulation, 15-20 fx.

To the naked eye the aethalia suggest F. septica var. Candida, but the
large, dark, irregularly roughened and often subreticulate spores dis-
tinguish it at once. A collection from New Mexico by Bethel, noted
as occurring directly on the hot desert sands as well as on the trunks
of Juniperus, is noteworthy for the extreme density and firmness of
the calcareous portion of the fructification and the paucity of spores.

Colorado, New Mexico, Florida; Africa. Not common.

2. Badhamia Berk, emend. Rost.
Mon. 139. 1875.
1852. Badhamia Berk., Trans. Linn. Soc. 21 : 153.

Sporangia simple or rarely plasmodiocarpous; peridium thin, break-
ing irregularly; capillitium composed of anastomosing tubules, forming
a network which is calcareous throughout, the nodes often only slightly
enlarged; stipe, when present, membranous or hair-like; columella
present or absent; spores in some species adherent in clusters.

The genus is closely related to Physarum but may ordinarily be
distinguished easily by the wholly calcareous capillitium. Individual
collections occur in which the capillitium may be more or less physa-
roid. Brandza (1926) cites certain extreme instances of this as a re-
sponse to the external conditions under which the sporangia are
formed. Howard (1931) shows that the capillitium of Physarum

26 THE MYXOMYCETES

polycephalum, in its development, goes through a badhamioid stage.
We are therefore justified in regarding Badhamia as the more prim-
itive of the two genera. Usually the distinction is readily apparent
in the mature sporangia.

KEY TO THE SPECIES OF BADHAMIA

a. Spores adherent in firm, globose clusters b

a. Spores free or only slightly and irregularly adherent /

b. Spores elliptical or oval 1. B. versicolor

b. Spores spherical or pyriform c

c. Sporangia yellow 2. B. nilens

c. Sporangia gray or white d

d. Stipitate, rarely sessile; stipe short, dark 3. B. papaveracea

d. Usually sessile; stipe, when present, yellow or straw

colored e

e. Sporangia gray, walls thin, translucent, white when empty;

spores warted 4. B. capsulifera

e. Sporangia white, rarely pale rose, calcareous; spores some-
times marked by bands or ridges 5. B. populina

f. Spores tending to adhere somewhat, but not in regular

clusters; iridescent 6. B. utricularis

f. Spores wholly free g

g. Spores ovoid; sporangia white or ochraceous, minute 8. B. ovispora

g. Spores typically spherical h

h. Sporangia yellow or yellowish *

h. Sporangia gray, white or iridescent j

h. Sporangia pale lilac or brown r

i. Sessile; dull yellow 9. B. decipiens

i. Stipitate; yellow-green or gray with a yellow base 10. B. viridescens

j. Spores warted with overlying coarse reticulation 14. B. gracilis

j. Spores not reticulate k

k. Sporangia flattened; discoidal to annulate or plasmodio-

carpous 12. B. orbiculata

k. Sporangia not greatly flattened, pulvinate, hemispherical or

subspherical /

/. Sporangia gray, iridescent, borne on long, slender, flaccid,

straw-colored stalks 7. B. magna

I. Stipes shorter, or lacking m

m. Spores usually over 15 n 11. B. qffinis

m. Spores usually under 15 n n

n. Sporangia ashy, heaped; spores very dark, coarsely and

densely spiny 15. B. cinerescens

n. Sporangia paler; spores more finely spinulose o

o. Sporangia white, stained with yellow or brown below; spores

dark, spinulose, 12-15 /x 13. B. macrocarpa

o. Sporangia without yellowish stains; spores paler, smoother

and smaller p

p. Capillitium dense, usually massed in center to form a

pseudocolumella 16. B. panicea

p. Capillitium less dense, not forming a pseudocolumella q

BADHAMIA 27

q. Sporangia usually sessile, sometimes with a short, yellowish,

flaccid stalk; spores dusky violaceous 17. B. foliicola

q. Always sessile on a broad base; spores grayish lilac; alpine. . 18. B. alpina
r. Sporangia pale lilaceous, rarely white; spores roughly

warted or subreticulate 19. B. lilacina

r. Sporangia grayish brown, stipitate; spores dark, rough-
ened, 12-14 n 20. B. rubiginosa

r. Sporangia darker, sessile; spores roughly warted, 15-18 n 21. B. subaquila

1. Badhamia versicolor Lister

Jour. Bot. 39 : 81. 1901.
PI. I, Fig. 14.

Sporangia minute, 0.2-0.5 mm. in diameter, scattered or clustered,
gray, flesh colored or occasionally white, sessile, the calcareous deposits
slight; capillitium white or apricot colored; spores ovoid 10-12 X 8-9 fx,
arranged in clusters of 10 to 40, forming hollow spheres or ellipses,
dull purple and minutely warted at the broad end, elsewhere paler and
nearly smooth.

This little species, as it comes to us, is gray, very uneven in size and
somewhat irregular in form and habit. The capillitium in our speci-
mens is white. The spores furnish the distinguishing character. They
are sometimes globose, about 9-10 /x. Most of them are definitely and
permanently affected in shape by the fact of cluster-association, nar-
rower in the direction of the cluster center. In typical forms, in which
they occur in hollow spheres, they are not pyriform or conical as in
other species with clustered spores, but oval in outline. Specimens
from Colorado referred here by Dr. Sturgis have the spores in smaller
solid clusters, easily broken apart. They may be distinct.

On the bark of living and dead trees, and on mosses and lichens in
such situations. Colorado, Ontario; Great Britain, Germany, Switzer-
land, Rumania, India.

2. Badhamia nitens Berk.

Trans. Linn. Soc. 21 : 153. 1852.
PI. II, Figs. 16, 17.

1852. Badhamia pallida Berk., Trans. Linn. Soc. 21 : 153.
1863. Badhamia inaurata Currey, Trans. Linn. Soc. 24 : 156.

Sporangia gregarious or closely crowded, globose or depressed-
globose, 0.5-1 mm. in diameter, yellow, greenish yellow or gray-
ish green, rugulose, sessile; capillitium yellow, forming an open net
with occasional thickenings at the nodes; spores clustered, delicately
roughened, violaceous brown, 10-12 i*. Plasmodium yellow.

28 THE MYXOMYCETES

This resembles Badhamia decipiens except for the clustered spores,
and the more commonly aggregate habit. The spores, as usual when
clustered, are conspicuously warted on the outer side, as noted by
the author of the species. In a collection from Isle Royale, Mich.
(Univ. Mich. Herb. Fl. 125) the peridium is double, the outer crustose
layer splitting away from the membranous inner layer and tending to
expand in petal-like lobes.

Michigan, Colorado, Montana, Oregon, California, West Indies,
South America; Ceylon, various parts of Europe.

Var. reticulata G. List., Trans. Brit. Myc. Soc. 5 : 71, 1914, forming
simple or netted plasmodiocarps on moss on the trunks of living trees,
occurs in Iowa, the West Indies and in the old world.

3. Badhamia papaveracea Berk. & Rav.

Grev. 2 : 66. 1873.
PL II, Figs. 18, 19.

1894. Badhamia hyalina (Pers.) Berk. var. papaveracea Lister, Mycetozoa 30.

Sporangia gregarious, globose or ovate, 0.7-1 mm. in diameter,
stipitate, iridescent-gray; peridium thin, translucent, and containing
but little calcareous deposit, smooth or slightly rugulose; stipe very
short, but generally distinct, black or very dark brown; hypothallus
none; capillitium a network of large meshes with expanded nodes,
prominent, white, persistent after the spores have been blown away;
spore-mass deep brown; spores pyriform, adherent as in B. capsulifera
and about the same size, 10-12.5 fx, but even more strongly warted or
echinulate on the exposed sides.

Distinguished by its short, dark stipe and adherent spores.

Not common. New England to South Carolina, Alabama, Wisconsin
and Iowa; Rumania, Japan.

4. Badhamia capsulifera (Bull.) Berk.

Trans. Linn. Soc. 21 : 153. 1852.
PL II, Figs. 20, 21.

1791. Sphcerocarpus capsulifer Bull., Champ. 139.

1801. Physarum hyalinum Pers., Syn. Meth. Fung. 170.

1805. Trichia capsulifera (Bull.) DC, Fl. Fr. 2 : 254.

1826. Physarum capsuliferum (Bull.) Chev., FL Par. 330.

1827. Physarum botryoides var. hyalinum Fr., Stirp. Femsj. 83.
1852. Badhamia hyalina (Pers.) Berk., Trans. Linn. Soc. 21: 153.
1892. Badhamia varia Mass., Mon. 319, in part.

Sporangia clustered or gregarious, sessile or sometimes stipitate,
globose or obovoid, gray or greenish white, snow-white when empty;

BADHAMIA 29

peridium thin, translucent; stipe, when present, as in B. utricularis,
although generally shorter and better developed, yellow or straw
colored; capillitium a very loose, open network of white, lime-filled
tubules, not much expanded at the nodes; columella none; spore-mass
purplish brown; spores adhering in clusters of five or six to twenty or
more, globose, but affected somewhat by mutual pressure, warted,
delicately where attached, more distinctly on the exposed surfaces,
10-12 ix. Plasmodium white to chrome yellow.

This includes Badhamia hyalina (Pers.) Berk., regarded by Rosta-
finski as distinct, but the latter admits that the two species, as he
defined them, are very much alike, having "the same spores and
capillitium," differing in the form of the sporangium, an inconstant
feature. Bulliard's name has precedence; his descriptions of this and
of B. utricularis are remarkable.

The adherent spores distinguish the species from B. utricularis;
and the sporangia sessile or with short but strand-like stipes, dis-
tinguish it from B. papaveracea. The plasmodia are small and hence
the resulting clusters of sporangia are of limited extent as compared
with a species such as B. utricularis which often fruits over a wide area.

The description as given applies to the typical European form. Col-
lections from Iowa and Colorado are white, aggregate, superimposed,
but have the capillitium and spores exactly as described for the type.
They approach B. populina as it occurs in Colorado and hence the
latter species has for years been referred to the Berkeley species. The
thicker and more strongly calcareous peridia constitute, as would
appear, the principal difference in the forms from Colorado. Such
differences are no doubt largely due to the drier meteorological condi-
tions of the western Mississippi valley; the climate is semi-arid as
compared with that of western Europe. Eastern Europe, on the other
hand, in its glacial history and meteorology, offers greater similarities,
as is brought out in Brandza's discussion (1929), and these similarities
are reflected in the striking similarity of the Myxomycete population
of the two regions.

Iowa, Colorado; Europe, Australia.

Var. repens G. List., Essex Nat. 18 : 319, 1918, characterized by
slender, curved plasmodiocarps, occurs in Rumania and Japan.

Var. arborea G. List., Mycetozoa ed. 3. 10, 1925, with small scat-
tered sporangia, 0.3-0.5 mm., and spores pale purplish gray, globose
or oval, 13-16 fx, is reported from Scotland.

Var. major Brandza, Bull. Soc. Myc. Fr. 44 : 252, 1929, is described
as sessile or with a short membranous stalk, the capillitium scanty or
lacking and the spores mostly free. Rumania.

30 THE MYXOMYCETES

5. Badhamia populesta Lister

Jour. Bot. 42 : 129. 1904.
PI. I, Fig. 15.

Sporangia white, sometimes pale rose, subglobose or ovoid, smooth,
calcareous, about 1.5 mm. in diameter, sessile and crowded, or rarely
solitary on short yellow-brown membranous stipes; capillitial strands
broad, calcareous; spores clustered, 16-20 or more in a cluster, purple-
brown, warted unequally, one side coarsely, the other faintly, and
usually marked by ridges and bands, 10-12 /z. Plasmodium said to be
white or cream colored.

Generally distinguishable by its unusually large, calcareous, white
or faintly rose colored sporangia. The peridial walls are shell-like in
texture. Very near B. capsulifera, but larger, the sporangia more
densely heaped and more calcareous and often with banded spores.
Collections from Colorado referred to this species are very near to
Iowa collections referred to B. capsulifera.

Colorado, Montana, Washington; Europe.

6. Badhamia utricularis (Bull.) Berk.

Trans. Linn. Soc. 21 : 153. 1852.
PI. II, Figs. 22, 23.

1791. Sphcerocarpus utricularis Bull., Champ. 128.

1797. Trichia coerula Trentep., in Roth, Cat. Bot. 1 : 229.

1803. Physarum ovoideum Schum., Enum. PI. Saell. 2 : 198.

1805. Physarum hyalinum var. chalybcBum Alb. & Schw., Consp. Fung. 92.

1805. Trichia utricularis (Bull.) DC, Fl. France 2 : 251.

1821. Trichia rubiformis Purt., non Persoon, in Brit. PI. of Midi. Count.
3 :291.

1825. Physarum botryoides Ft., Stirp. Femsj. 83.

1826. Physarum utriculare (Bull.) Chev., Fl. Paris 1 : 337.
1826. Physarum botrytes Somm., Fl. Lapp. 242.

1832. Diderma papaverinum Wallr., Fl. Crypt. Germ. 375.
1892. Badhamia varia Massee, Mon. 319, in part.

Sporangia clustered, spherical, ovoid or pyriform, large, 0.7-1.0 mm.
in diameter, sessile or mounted on long, thin, strand-like stalks, blue-
gray, violet-iridescent or cinereous, smooth or more often rugulose;
peridium iridescent, hyaline or white when empty; stipes when present
poorly differentiated, thread-like filaments as if representing strands
of the Plasmodium, often branched and usually reclining or even
prostrate; hypothallus none; capillitium a large-meshed open network
of rather slender tubules, the nodes unequally developed, white with
the^enclosed lime; spores nearly free although not without some

BADHAMIA 31

tendency to stick together, uniformly and distinctly warted, bright
violet-brown, 10-12 /*.

This species resembles B. capsulifera, but is distinguished by a more
strongly rugulose, less calcareous peridium and a more profuse develop-
ment of filamentous stipes, but especially by the character of the spores.
The spores of the present species while inclined, when mounted in a
liquid, to stay together, only occasionally occur in regular clusters,
nor do they show any differentiation in the episporic markings, these
being uniform over the entire spore.

This is one of the finest and perhaps the most beautiful species of
this fine genus, the Plasmodium being very large and resulting in
extensive areas of fructification. It is a forest species, generally to be
found on trunks of fallen Populus or Tilia where the fine soft gray
colonies often spread for several inches along the ridges and in crevices
of the bark. Often on fungi and sometimes on lichens.

Washington, Montana, Colorado, Mississippi valley and east, Bo-
livia; Europe, South Africa, Australia.

7. Badhamia magna Peck

Rept. N. Y. State Mus. 31 : 57. 1879.
PI. II, Figs. 24, 25, 26.

1872. Dictydium magnum Peck, Rept. N. Y. State Museum 24 : 84.
1892. Badhamia varia Massee, Mon. 319, in part.

1899. Badhamia capsulifera (Bull.) Berk, ex Macbride, N. A. Slime-Moulds
68, in part.

Sporangia globose or ellipsoid, 0.7-1 mm., bluish gray, iridescent,
stipitate; peridium thin with slight calcareous deposits, rugulose,
opening irregularly, white; stipe long, flaccid, straw colored; capillitium
an elegant uniform net, its threads stiffened by slight deposits of lime,
the nodes little thickened; spores free, dusky with a shade of violet,
finely warted or spinulose, spherical, 11-12 /z, or oval, 14-15 X 11-12 ja.

Closely resembling some forms of B. utricularis, from which it may
be distinguished by its unclustered and smoother spores and its long,
slender, pale stipes. B. foliicola, as here recognized, is very close, but
smaller and with short stems. The spores from the type collection,
Center, N. Y. (not Vermont, N. Y., as cited by Lister), are distinctly
oval, and large, 14-15 X 11-12 n, with a prominent pale umbo at one
end, probably indicating the area of dehiscence. Other collections re-
ferred here have spherical or nearly spherical spores.

The eastern United States and Canada; Rumania. Not rare. In the
eastern United States it seems to occupy much the same place that
B. capsulifera does in Europe.

32 THE MYXOMYCETES

8. Badhamia ovispora Racib.

Rozpr. Mat.-Przyr. Akad. Krak. 12 : 72. 1884.
PI. II, Fig. 33.

Sporangia minute, 0.5 mm. in diameter or less, sessile, depressed-glo-
bose or plasmodiocarpous, white or ochraceous, sometimes on a dark
red hypothallus; sporangium wall thick, calcareous, often scaly; capilli-
tium white, often denser at the center to form a pseudocolumella; spores
free, pale purple-brown, elongate, ellipsoidal or irregular, 10-15 X 8-10 //.

On old straw, dead wood, rabbit dung, etc. Not common. Pennsyl-
vania, Massachusetts; Europe.

9. Badhamia decdpiens (Curtis) Berk.

Grev. 2 : 66. 1873.

PI. II, Figs. 27, 28.
1848. Physarum decipiens Curtis, Am. Jour. Sc. II. 6 : 352.
1873. Physarum chrysotrichum Berk. & Curtis, Grev. 2 : 66.
1876. Badhamia chrysotricha (Berk. & Curtis) Rost., Mon. App. 4.

Sporangia gregarious, depressed-spherical or ovate, sessile, occa-
sionally plasmodiocarpous, dull yellow, roughened by the rather nu-
merous calcareous scales; columella none; capillitium dull orange,
strongly calcareous, only slightly widened at the nodes, sometimes
somewhat physaroid; spore-mass black; spores free, pale violet, very
minutely spinulose, 10-12 jx. Plasmodium yellow.

Among free-spored badhamias this and the next species are at once
distinguished by the color and the globose spores. If the original de-
scription can be regarded as denning anything, this is the same as
Physarum chrysotrichum B. & C. It resembles somewhat Physarum
serpula Morg., but differs externally in color and in the surface scales,
which are not perceptible in the Physarum. The present species also
resembles Cienkowskia reticulata (A. & S.) Rost., but has a different
capillitium. See under that species.

According to Brandza (1929), when development occurs under moist
conditions the colors are paler and the capillitium distinctly bad-
hamioid, while under dry conditions the color becomes orange-yellow
and the capillitium more or less physaroid.

Chiefly eastern and American. New England, Pennsylvania, Ohio,
South Carolina, Bolivia; reported also from western Europe and
Rumania.

10. Badhamia viejdescens Meylan

Bull. Soc. Vaud. Sc. Nat. 53 : 452. 1921.
Sporangia scattered or loosely clustered, stalked, subglobose,
0.5-0.8 mm. in diameter, yellow-green or gray with a yellow or red-

BADHAMIA 33

dish base, rugulose; sporangium well spotted and veined with lime
granules, thicker and orange-yellow near the base; stalk yellow or
yellowish red, sulcate, free from refuse deposits, 0.1-0.3 mm. high;
capillitium a network of tubes enclosing pale yellow or white lime
granules, with a few hyaline connecting threads; spores pale brownish
violet, very minutely warted, 10-13 ju.

According to the author, partly or completely limeless forms may
occur.

Scotland, Switzerland.

11. Badhamia affinis Rost.

Mon. 143. 1875.
PI. II, Fig. 34.

Sporangia aggregated, often caespitose, discoidal to subspherical,
sessile or short-stipitate, flat or umbilicate below, about 0.5-0.8 mm.
in diameter; wall grayish white, rugulose and more or less calcareous
and scaly; the stalk, when present, erect or sometimes nodding, 0.1 to
0.7 mm. tall, black or brownish black; hypothallus scanty, columella
lacking; capillitium not abundant, white, the nodes somewhat ex-
panded; spores globose, minutely but densely spinulose, violet-brown,
averaging 16-17 fx in diameter. Lister cites the spore measurements as
10-15 /z; Schintz as 12—15 /x. Material collected by Morgan in Ohio,
and otherwise typical, has spores 16.5-18.5 fx in diameter.

Chiefly on moss, the small, pale, ashen sporangia appearing on the
tips of the leaves. Specimens from Kansas, here referred, have pale,
rugose stipes, about twice the height of the sporangium.

Not common, but cosmopolitan. Reported from New York, Ohio,
Kansas, South America; Europe, Asia, South Africa.

12. Badhamia orbiculata Rex

Proc. Acad. Nat. Sc. Phila. 1893 : 372.
PI. II, Figs. 29, 30.

1894. Badhamia macrocarpa (Ces.) Rost. ex Lister, Mycetozoa 33, in part.
1925. Badhamia affinis Rost. var. orbiculata G. List., Mycetozoa ed. 3. 16.

Sporangia stipitate or sessile, orbicular, discoidal, irregularly elon-
gated or plasmodiocarpous, averaging about 1 mm. in width, generally
stipitate, and when stipitate, flattened or depressed above, plane or
slightly umbilicate below; peridium simple, more or less translucent
from the varying number of innate granules, sometimes covered with
circular flat masses of lime, gray except the point of attachment to the
stipe, which is brown; stipe short, black, rough, plicate; capillitium

34 THE MYXOMYCETES

dense at the center, radiant at the periphery where it meets the spo-
rangial wall, white; spores violaceous black, minutely warted, 12-14 /x.
Plasmodium cream to pale yellow.

This is a beautiful species, easily known by its discoidal or almost
annulate sporangia mounted upon short, dark stipes. The stipe
in western collections is sometimes very short, but generally suffices to
raise the sporangium, a little at least, above the substratum. Sessile
and plasmodiocarpous forms do occur with the typical stipitate phase,
but may be regarded here as elsewhere as indicative of incomplete
development. Miss Lister regards this as a variety of B. affinis, to
which species it undoubtedly is related. But its larger size, somewhat
smaller spores and slight but apparently constant differences in perid-
ium and capillitium seem to justify its retention as a distinct species.

Pennsylvania, Ohio, Iowa, Nebraska, South Dakota, Colorado,
Antigua; Malay Peninsula, Manchuria, Japan.

13. Badhamia macrocarpa (Ces.) Rost.

Mon. 143. 1875.
PI. II, Figs. 31, 32.

1855. Physarum macrocarpon Cesati, Flora 38 : 271.

Sporangia scattered, closely aggregate or crowded, globose or sub-
globose, 0.5-1.0 mm. in diameter, sessile or with a pale yellowish or
brownish furrowed or submembranaceous stalk; peridium rugulose,
white above, below yellowish or brownish; capillitium not abundant,
thoroughly calcareous, the nodes broad, conspicuous, the connecting
tubules rigid; columella none; hypothallus scant or none; spore-mass
black, spores non-adherent, by transmitted light dark violet-brown,
finely but densely and somewhat irregularly spinulose all over, spher-
ical, 11-14 /d.

Externally closely resembling B. panicea, but easily distinguished by
the larger, more spinulose spores. European authors describe both
sessile and stipitate forms. American specimens generally are sessile
and for the most part closely crowded, almost heaped. Professor
Bethel has reported this in winter everywhere on fallen rotting stems
of Opuntia and on the bases of dead Yucca leaves, still attached.
Occasionally associated with the typical phase and often occurring
alone was a discoidal form which when first seen (in 1908) was called
var. gracilis, under which name Miss Lister distinguishes it. Further
study suggests that the latter is best regarded as a distinct species, as
it differs not only in its external characters but in its spores, which in
gracilis are not only warted, but possess a coarse reticulation in addi-

BADHAMIA 35

tion. There is no evidence, in the abundant material at hand, that the
two forms, although perhaps sometimes associated, arise from the
same Plasmodium.

Badhamia mandshurica Skvortz., Phil. Jour. Sc. 46 : 86, 1931, refers,
perhaps, to a small, dark, heaped phase of B. macrocarpa.

Throughout the United States, Bolivia; Europe, Java, Japan.

14. Badhamia gracilis Macbride n. sp.

PL III, Figs. 37, 38.

1913. Badhamia macrocarpa Rost. ex Sturgis, Colo. Coll. Pub. Sc. Ser. 12 : 438,
in part.

1922. Badhamia macrocarpa (Ces.) Rost. var. gracilis Macbr., N. A. Slime-
Moulds ed. 2. 37.

Sporangia gregarious or clustered, globose or ovate, 0.5-0.7 mm.
in diameter, stipitate or sessile, gray when filled with spores; peridium
thin, pure white, sparsely flecked with white calcareous nodules; stipe
when present thin, delicate, straw yellow, sulcate, more or less twisted,
about equal to the sporangium; capillitium a delicate mesh work of
tubules of nearly uniform diameter; hypothallus scanty, pale yellow-
ish; spores free, globose or somewhat angular, dark violaceous brown,
closely and irregularly warted, and mostly with a very coarse network
of about 1-6 meshes to the hemisphere covering the surface,
12-15 fi.

The combination of close warts and coarse reticulum on the spore
wall is distinctive, although suggested by the spores of B. populina,
B. cinerascens and B. lilacina. Most of our material is on Yucca or
cactus; the Iowa collection on bark.

Iowa, Colorado, New Mexico, Arizona, California and the West
Indies.

15. Badhamia cinerascens Martin

Jour. Wash. Acad. Sc. 22 : 88. 1932.
PL III, Fig. 44.

Sporangia globose or flattened, sessile or occasionally borne on a
pallid, membranous stipe, 0.7-1.5 mm. in diameter, densely aggregated
and more or less superimposed, on a pallid membranous hypothallus;
peridium thin, fragile, ashy, covered by a dense network of calcareous
thickenings; capillitium abundant, white, badhamioid under lens, but
under the microscope exhibiting numerous thread-like tubules; spores
intensely black in mass, spherical or somewhat angular, non-adherent,
deep purple-brown by transmitted light, densely and strongly spinu-
lose, and often exhibiting an imperfect, coarse reticulation, always with

36 THE MYXOMYCETES

a paler area of dehiscence, 12-15 ix, averaging 13.5 n of which 2 jj, repre-
sents the spiny margin.

Close to B. macrocarpa and B. gracilis, and like these and re-
lated species with a more or less physaroid capillitium, but dis-
tinguished by its ashy color, the heaped sporangia and the extremely
dark, coarsely and densely spiny spores. In appearance not unlike
some specimens of Physarum cinereum, but the capillitium distinctly
more badhamioid than physaroid, and the spores much larger, darker
and rougher.

Colombia.

16. Badhamia panicea (Fr.) Rost.

ex Fuckel, Symb. Myc. Nachtr. 71. 1873.
PL III, Figs. 35, 36.

1829. Physarum paniceum Fries, Syst. Myc. 3 : 141.

1847. Reticularia schmitzii Debey, Verh. nat. Ver. preuss. Rheinl. 1:1.

1873. Badhamia vema (Somm.) Rost. ex Fuck., Symb. Myc. Nachtr. 145, in part.

Sporangia white or cinereous, gregarious, or aggregated in closely
compact clusters, globose or hemispherical, 0.4-1.2 mm. in diameter,
sessile; hypothallus scanty, inconspicuous, very dark red, rarely with
a short, red stalk; peridium thin, thickly dotted with white calcareous
scales; columella none, although a pseudocolumella often appears,
formed by a more dense development of the capillitium near the center
of the lower part of the sporangium; capillitium abundantly developed,
quite uniformly thickened, but showing an occasional delicate con-
necting thread, the nodes also somewhat flattened and enlarged;
spore-mass black; spores free, by transmitted light bright violaceous
brown, minutely punctate, 11-13 /x. The plasmodium is said to be
white. Miss Lister separates forms having spores which are dark on
one side and paler on the other as var. heterospora.

In America this seems to be mainly a western species. Specimens
are before us from western Iowa and from Colorado, South Dakota,
Nevada, Oregon, southern California and Europe. It is very well
marked, though liable perhaps to be mistaken at first sight for sessile
phases of Physarum notabile or P. cinereum. The capillitium is, how-
ever, at once determinative. In addition to the states mentioned,
reported from Washington, Bolivia, Argentina.

Var. nivalis Meylan is reported as occurring at the margin of snow
banks in Switzerland.

B. goniospora Meylan, Bull. Soc. Vaud. Sc. Nat. 56 : 66, 1925,
lacks a hypothallus and has larger, somewhat irregular spores. It is

BADHAMIA 37

said to differ from B. panicea in the color of the Plasmodium, and the
larger, darker, more irregular spores, and from B. foliicola in the spore
characters and the whitish gray sporangia.

17. Badhamia foliicola List.

Jour. Bot. 35 : 209. 1897.

Sporangia 0.5-0.6 mm. in diameter, subglobose or ellipsoidal, irides-
cent-gray, stipitate or sessile; peridium thin, rugulose, sparingly cal-
careous, when empty white; stipe when present short, yellowish,
flaccid; capillitium badhamioid; spores free, delicately spinulescent,
dusky violaceous, 11-12 n. Plasmodium orange.

If Badhamia microcarpa Schroet, Krypt. Fl. Schles. 3 (1) : 131,
1886, should prove to be the same, as is suggested by Lister and Schinz,
that name would take precedence. Mr. Hagelstein reports the species
as common on Long Island. The color of the Plasmodium, quoted
from Miss Lister, is of importance only when constant and confirmed
by other criteria.

Meylan, Bull. Soc. Vaud. Sc. Nat. 57 : 301, 1931, reports a yellowish
phase from Switzerland which he calls form flavescens.

New York, Ontario, Iowa, Oregon; Europe, Australia.

18. Badhamia alpina G. List.

Jour. Bot. 52 : 99. 1914.

Sporangia scattered or clustered, sessile, subglobose or hemispherical
on a broad base, 0.5 to 0.9 mm. in diameter, gray or iridescent, usually
seated on a dark hypothallus; capillitium a close network of slender
tubes enclosing scanty deposits of lime; spores free, grayish lilac,
almost smooth or very minutely warted, 10-12 fj.. Plasmodium pale
yellow or yellowish white.

This description is from Lister. Close to B. foliicola, differing in
pale color of plasmodium, more hemispherical sporangia and paler,
smoother spores.

Known from the Alps and Sweden. Not yet reported from North
America.

19. Badhamia lilacina (Fr.) Rost.

Mon. 145. 1875.
PI. Ill, Figs. 39, 40.

1829. Physarum lilacinum Fr., Syst. Myc. 3 : 141.
1892. Craterium lilacinum Massee, Mon. 271.
1892. Physarum concinnum Massee, Mon. 308.

38 THE MYXOMYCETES

Sporangia globose, subglobose or obconical, sessile, gregarious or
more or less clustered, supported by a thin, continuous transparent
hypothallus; peridium smooth, pale lilac-brown or almost white with-
out, paler or white within; stipe none, although some sporangia have
a narrowed base; columella none, the pseudocolumella formed by a
more densely aggregated capillitium near the base; capillitium dense,
white, strongly nodulose; spore-mass black; spores free, dark, vio-
laceous brown by transmitted light, covered with rough warts and
ridges, sometimes subreticulate, 10-15 /i.

Easily recognizable, generally at sight, by its peculiar color. White
forms, however, occur; often lilac-tinted and white from the same
Plasmodium. A perfectly white colony seems to be rare. Both colors
are shown in specimens distributed. Whatever the color, the spores
are in every case positively diagnostic. The episporic markings are
unlike those of any other species in the genus. Rex described some
New York forms as provided with a short but distinct stipe. Such
forms bear a superficial resemblance to pale forms of B. rubiginosa.
The hypothallus also is unique.

Common eastward. New England to Pennsylvania, Ontario, Ohio.
Not reported west of the Mississippi. Also Europe, where it seems
to be less common.

20. Badhamia rubiginosa (Chev.) Rost.

Mon. App. 5. 1876.
PI. Ill, Figs. 41, 42, 43.

1826. Physarum rubiginosum Chev., Fl. Par. 338, non Fr. 1817.

1874. Craterium obovatum Peck, Rept. N. Y. State Mus. 26 : 75.

1875. Scyphium rubiginosum (Chev.) Rost., Mon. 148.
1892. Craterium rubiginosum Massee, Mon. 270.

Sporangia gregarious, obovoid, grayish brown, stipitate; peridium
simple, membranous, above thin, pale, more or less calcareous, below
more persistent, blending with the stipe; stipe erect, reddish brown or
purplish, expanded below into a small hypothallus, above prolonged
within the sporangium more than half its height as a definite columella;
capillitium very dense, snow-white, long-persistent with the lower
two-thirds of the sporangial wall; spore-mass dark brown; spores by
transmitted light dark violet or purple-brown, distinctly warted, not
adherent, 12-14 jx.

This is probably the most common badhamia in North America.
It is found on masses of decaying leaves, especially those of various
species of oak. The Plasmodium is yellow. The fructifications are
very distinct, not likely to be mistaken for those of any other species;

BADHAMIA 39

the stipes constitute a very prominent feature in every gathering in
our collection. Sometimes these are more or less coalescent, especially
toward the base, where they are apt to be also wrinkled or longitudi-
nally striate; in other specimens the stipes are well differentiated, long,
terete, with little or no hypothallus.

Badhamia curtisii (Berk.) Rost. is according to Lister a sessile
phase of this species. The only specimens known are in the herbarium
of Berkeley, now at Kew. The species is based upon a gathering from
South Carolina. Berkeley thought it a didymium and called it
D. curtisii, Massee regarded it as a craterium.

Badhamia dictyospora Rost., Mon. App. 4, 1876 {Craterium dictyosper-
mum Massee, Mon. 270, 1892), with obovoid sporangia, and spores
coarsely warted or subreticulate, is reduced to varietal rank by Lister.

Var. globosa Lister, Jour. Bot. 42 : 130, 1904, is described as having
subglobose, stipitate sporangia, dark columella and strongly reticulate
spores. A collection from North Wales, so determined by Dr. Elliott,
has as many obovate as globose sporangia, but the large, dark spores
are beautifully reticulate.

Abundant in the forested regions of North America, especially in
the Mississippi valley. Also western Europe, Poland and Rumania.
The varieties not reported from North America, but recorded from
Europe, Japan, South Africa, Hawaii.

21. Badhamia subaquila Macbr.

N. A. Slime-Moulds 64. 1899.

Sporangia closely gregarious or crowded, globose or subglobose,
sessile, brown; peridium a thin but persistent brown membrane, rup-
turing above irregularly and remaining as a cup after spore dispersal;
hypothallus none; capillitium strongly developed, thoroughly cal-
careous, the meshes large, the nodular thickenings broad, white;
spores globose, in mass black, by transmitted light brown, very rough-
warted, large, 15-18 fx.

The species is founded on material sent from Maine by the late
Mr. F. L. Harvey. Professor Harvey, upon the authority of Morgan,
cites the species (Bull. Tor. Bot. Club, 24 : 67) as B. verna (Somm.)
Rost. But the specimens certainly do not conform to the description
of B. verna. The wall corresponds with that of B. rubiginosa; but the
spores are much larger, and the capillitial structure very different.

Miss Lister regards this as a form of B. rubiginosa. So far, the
original gathering represents the species; but the woods of Maine are
certain one day to send added information.

Maine. Rare.

40 THE MYXOMYCETES

3. Erionema Penzig
Myx. Buitenzorg 36. 1898.

Sporangia plasmodiocarpous, cylindrical, simple or branched; cap-
illitium a network of slender colorless threads, elastic; nodules few and
small.

Erionema aukeum Penzig

Myx. Buitenzorg 37. 1898.

Sporangia elongate, clustered, pendulous, yellow or grayish yellow,
generally stipitate on long flaccid stalks, or sessile and interlacing;
stipes yellow, blending with the hypothallus; capillitium intricate,
expanding at maturity after the manner of Arcyria to several times
the sporangial length, the nodules small, yellow; spores nearly smooth,
violaceous brown, 5-6 ix.

This unique form is near the fuligos, which it closely resembles,
especially when sessile. The spores also are much like those of the
common Fuligo septica. The habit is, however, entirely different.
Petch described clusters in Ceylon, hanging free, four to six cm. in
length !

Known only from Japan, Java, Malay Peninsula and Ceylon.

4. Physarum Per soon emend. Rost.

Mon. 93. 1875.
1794. Physarum Pers., Roemer N. Mag. Bot. 1 : 88, in part.

Sporangia distinct or plasmodiocarpous, rarely almost aethalioid;
peridium usually simple, sometimes double, irregularly dehiscent,
more or less calcareous; capillitium in the form of a uniform but ir-
regular network of calcareous nodules connected by hyaline thread-like
tubules, adherent on all sides to the peridial wall.

The distinctive characters are the structure of the capillitium and
the irregular dehiscence. The peridium, sometimes almost limeless,
is usually encrusted with lime, which is always amorphous, never
crystalline. The sporangia may be sessile or stipitate; the stipe, when
present, may be solid or hollow and charged with lime.

As first proposed by Persoon, the genus included diverse forms. He
made its limits more definite in 1795 and 1801 and in 1829 Fries
further delimited it and set aside certain species as constituting the
genus Tilmadoche. Rostafinski altered Fries' arrangement, retaining
both genera, but recent writers have been agreed that the separation
is artificial and have discarded Tilmadoche. Rostafinski 's treatment,

PHYSARUM 41

however, had certain advantages of convenience. One possible solu-
tion seems to be to treat the genus Physarum as a whole, but to
segregate the species into two sections, Euphysarum and Tilmadoche.
In using the key, it should be borne in mind that a number of
sessile species may be somewhat plasmodiocarpous in some collec-
tions, and that stipitate species may be sessile at times. For the pur-
poses of the key, each species is placed under what is believed to be
its more representative expression.

KEY TO THE SPECIES OF PHYSARUM

Capillitium irregularly reticulate; lime-knots various,

typically large and irregular I. Section Euphysarum

Capillitium regular, forked and radiating; lime-knots

smaller, fusiform II. Section Tilmadoche

I. Euphysarum

a. Fructification sessile, often plasmodiocarpous b

a. Fructification sporangiate, stalked I

b. Peridium single, or, if double, inner peridium very delicate and closely

attached to outer c

b. Peridium plainly double h

c. White or cinereous d

c. Some shade of yellow or green e

c. Orange-red, red or brown /

c. Dark gray, dull violet, blue or iridescent g

d. Peridium granular; spores sometimes oval 1. P. ovisporum

d. White or gray, calcareous; spores dark, rough, 9-12 it 2. P. vernum
d. Cinereous; wall thin, delicate; spores bright lilac,

finely spinulose, 7—11 yu, 3. P. cinereum

d. Sessile, but narrowed at base; lime forming a fine

reticulation over surface 4. P. gilkeyanwm

d. Sporangia depressed, annulate or umbilicate above,

rarely with short stalks; spores 12-15 /x 5. P. megalosporum

d. Gray, sometimes slightly bluish; peridium smooth;

spores pale, 6-8 /x 6. P. sessile

e. Pale yellow to ochraceous; spores 10-13 // 7. P. serpula

e. Bright yellow; spores 9-12 y. 8. P. aureum

e. Yellow or greenish yellow to green; spores 7-10 /x 9. P. virescens

f. Vermilion or scarlet; lime-knots rounded, yellow, often

with red centers 10. P. lateritium

f. Rusty or reddish brown; lime-knots angular, dull red

or yellowish 11. P. rubiginosum

f. Tawny or clay colored; very small, crowded; spores

6-7 fj, 12. P. digitatum

f. Brownish orange or chestnut; spores 10-12 /z 13. P. famintzini

■.,. Dull violet-brown; small, densely clustered and super-
imposed 14. P. confertum

;. Blue-gray, iridescent; lime in form of flat scales 15. P. lepidoideum

42 THE MYXOMYCETES

g. Dull'gray, somewhat iridescent; limeless 16. P. nudum

h. Red 16a. P. nasuense

h. White or pallid *

h. Yellow or ochraceous j

h. Some shade of brown k

i. Laterally compressed, chalk white; spores sub reticulate. . 17. P. echinosporum

i. Laterally compressed, white or gray, sometimes yellow-
ish; inner peridium colorless or pallid 18. P. bivalve

i. Somewhat compressed or terete, white or pallid; inner

peridium purplish 19. P. bitectum

i. Hemispherical, rarely laterally compressed, snow-white;

outer peridium diderma-like, remote 20. P. diderma

j. Pale yellow to yellowish white; plasmodiocarpous ;

spores 9-14 n 21. P. alpinum

j. Ochraceous, sporangiate; peri dial walls distant;

spores 8-10 /x 22. P. conglomeratum

j. Deep ochraceous to pallid; short-plasmodiocarpous

to reniform, densely crowded; spores spinulose, 11-13 \x 23. P. contextum
j. Ochraceous to pallid ; usually sporangiate, not crowded ;
outer peridium breaking up into scales, inner peridium
persistent below; spores warted, 11-13 n 24. P. mortoni

k. Sporangiate; sessile or short-stalked, rarely plasmodio-
carpous; lower part remaining as a cup 25. P. brunneolum

k. Usually plasmodiocarpous; pinkish brown or bronze. ... 26. P. aneum

k. Usually plasmodiocarpous; outer peridium yellow-brown,
dehiscing by triangular lobes revealing the pure white

inner surface 27. P. bogoriense

I. Columella large, conspicuous tn

I. Columella small, conical, sometimes imperceptible n

I. Columella lacking, pseudocolumella sometimes present q

m. Columella long, slender, acuminate; sporangia ellip-
soidal, greenish 28. P. penetrate

m. Columella cylindrical; sporangia pink 29. P. puniceum

m. Columella stout, cylindrical or clavate, sometimes re-
duced; sporangia globose, grayish white or pale brown. . 30. P. crateriforme

m. Columella subglobose or clavate, yellow 31. P. listen

m. Columella white, conical, attaining one-third the height

of the sporangium; stipe stout, yellowish 32. P. perjectum

n. Sporangia pale bluish gray to white; nodes white or

yellowish 33. P. globuliferum

n. Sporangia ashy brown; nodes orange to brownish. ... 34. P. murinum

n. Sporangia yellow or orange °

n. Sporangia lilac to purple or blue P

o. Honey yellow; columella and stipe white, yellow or

tawny; nodes white 35. P. melleum

o. B right yellow; columella and stipe yellow; nodes yello w. . 36. P.citrinum

o. Yellow-orange to bronze tawny; stipe orange-red, darker

at base 37. P. pulcherripes

p. Sporangia and stalk deep purple-red; nodes small,purple 38. P. pulcherrimum
p. Pale lilac to pale red, rarely blue 39. P. lilacinum

PHYSARUM 43

q. Sporangia with a conspicuous, white calcareous nucleus

at center r

q. Sporangia non-nucleate s

r. Globose, white; peridium membranous, capillitium

dense 40. P. nucleatum

r. Gray or brown; capillitium delicate 41. P. wingatense

r. Ovoid or cylindric, crowded; outer peridium white,
calcareous, sometimes lacking; inner peridium lead

colored; spores 12-15 fi 42. P. didermoides

r. Lime mass often columella e; stalked, sessile or plas-

modiocarpous; spores 7-10 ju 43. P. mutabile

r. Sporangia multilobate, contorted 44. P. nicaraguense

r. Discoidalor top-shaped, depressed or umbilicate above 45. P. discoidale

s. Sporangia not globose or lenticular t

s. Sporangia globose, subglobose or lenticular «

t. Sporangia white; thin, saucer-shaped 46. P. javanicum

t. Sporangia white or ashy; laterally compressed, circu-
lar to reniform, sometimes sessile and almost plas-

modiocarpous 47. P. compressum

t. Sporangia pale purple; obovate or wedge-shaped;

stipe pallid, weak, often flattened 48. P. straminipes

u. Brilliant purple; short-stemmed, sometimes sessile 49. P. newloni

u. Rose-red; stipe exceeding sporangium 50. P. roseum

u. Blue or bronze, iridescent, spotted with red or orange;

stipe brilliant orange 51. P. psittacinum

u. Gray, white or iridescent v

u. Yellow or yellowish w

v. Stipe snow-white, fragile; peridium didymium-like. . . 52. P. leucopus
v. Stipe pale fuscous to brown, stout, short, wrinkled;

peridium white to bluish 53. P. leucophceum

v. Stipe bright yellow; nodes small, yellow 54. P. maculatum

v. Sporangia depressed-globose, stipitate or sessile,
strongly calcareous; stipe dark, opaque, sometimes

frosted with white granules 55. P. notabile

v. Stipe long, slender, bright brown; sporangia nearly

globose, rather small, 0.4-0.6 mm 56. P. pusillum

v. Stipe shorter, robust, dark; sporangia larger, irides-
cent, with scanty lime deposits 57. P. tropicale

w. Color dull; pale, ochraceous, fulvous to nearly black x

w. Bright yellow y

x. Dull yellow to dusky; minute; spores 7-9 /x 58. P. simplex

x. Yellowish white to fulvous; stipe weak, often lacking;

spores dark, rough, 12-15 n 59. P. albescens

x. Pale or deep ochraceous; spores violaceous, 10-12.5 y. 60. P. citrinellum
x. Dingy yellow to brownish ochraceous, often obovate

or cylindrical; stipe short 61. P. variabile

x. Peridium membranous, ochraceous above, lower part

and stipe with flesh tints 62. P. carneum

x. Yellowish to sooty, often iridescent 63. P. flavicotnum

x. Sulphur-yellow to olive-yellow; nodes large, white. . . 64. P. sulphur eum

44 THE MYXOMYCETES

y. Golden yellow; capillitium yellow, badhamioid; stipe

short or lacking 65. P. auriscalpium

y. Pale yellow or straw colored, rarely gray; dehiscence

petaloid; stipe slender; nodes small, rounded 66. P. tenerum

y. Golden yellow; peridium thin; capillitium dense, yellow,

the nodes few, small and angular 67. P. galbeum

y. Peridium bright yellow, rough; nodes yellow, dense, con-
nected by yellow or hyaline threads 68. P. oblatum

II. TlLMADOCHE

o. Plasmodiocarpous, almost aethalioid 69. P. gyrosum

a. Sporangiate, stalked &

b. Sporangia compound, gyrose 70. P. polycephalum

b. Sporangia single c

c. Spores reticulate; sporangia dull orange to brown 71. P. dictyospermum

c. Spores not reticulate <*

d. Gray or white, nodding 72. P. nutans

d. Yellow, greenish yellow or rusty orange; nodding. ... 73. P. viride
d. Iridescent-blue with pale yellow scales; usually erect

on short stipe 74. P. bethelii

d. Yellow, orange or iridescent; lenticular, often um-

bilicate; capillitium rigid, rod-like 75. P. rigidum

1. Physarum ovisporum G. Lister

Jour. Bot. 51 :91. 1921.

Sporangia scattered, sessile, pulvinate or forming straight, curved
or irregular plasmodiocarps, 0.5 to 0.8 mm. in diameter, white; spo-
rangium wall minutely roughened with deposits of lime granules, often
with smoother areas where the lime deposits are scanty; capillitium
consisting of numerous white, rounded lime-knots, varying much in
size, connected by short hyaline threads; spores rich purple-brown,
minutely warted, either globose, 9-11 ju, or oval, 12-13 X 10 fx, often
with a pale smooth line of dehiscence. Plasmodium white.

The above description is based on that of Miss Lister. Specimens
from Switzerland, collected and determined by Meylan, have globose
spores 9 [x in diameter with no visible area of dehiscence, and closely
resemble some forms of P. cinereum, differing only in the longer
plasmodiocarps and the somewhat more limy wall.

England, Switzerland.

2. Physarum vernum Somm. ex Fries

Syst. Myc. 3 : 146. 1829.
PI. XXI, Fig. 559.
1875. Physarum cinereum (Batsch) Pers. ex Rost., Mon. 102, in part.
1875. Badhamia verna (Somm.) Rost., Mon. 145, in part.
Sporangia sessile, generally plasmodiocarpous, white, nearly smooth,
0.5-1 mm. in diameter; peridium firm, usually double, the inner

PHYSARUM 45

membranous layer closely applied to the limy outer coat, not scaly,
but breaking irregularly; capillitium densely calcareous, the nodules
angular, branching, sometimes united to form a pseudocolumella;
spores dusky violaceous, rough, 9-12 jx. The plasmodium is said to
be white.

Sommerfeldt's description, quoted by Fries, evidently concerned a
less calcareous phase. Fries by his annotation relieves somewhat the
reader's uncertainty. Rostafinski calls this a badhamia but describes
a physarum, and the form has frequently been confused with P. cine-
reum from the days of de Bary until now. In the second edition of the
Mycetozoa, Lister clears the situation by transferring the species to
Physarum, and calling attention to spore dimensions. From all con-
nection with Badhamia, as representing B. panicea, it should, as would
appear, be withdrawn once and for all.

Mainly an old-world species. Many of the American collections so
referred are better regarded as forms of P. cinereum with large spores.
The European material in our collection is more definitely plasmodio-
carpous and seems to have a much firmer wall, even in the less cal-
careous forms referred to as var. iridescens Lister. Whether all large-
spored collections from America should be referred to P. cinereum
is doubtful, however. Our only American specimens were sent by
Mr. Hagelstein from Long Island.

New York, Washington, Cuba; Europe, South Africa, Hawaii,
Australia.

Var. iridescens G. Lister lacks the limy outer coat, and, in material
furnished by Miss Lister, is less plasmodiocarpous. Europe.

3. Physarum cinereum (Batsch) Pers.

Roemer N. Mag. Bot. 1 : 89. 1794.
PI. Ill, Figs. 45, 46.

1786. Lycoperdon cinereum Batsch, Elench. Fung. Cont. 1. 249.

1809. Physarum griseum Link, Mag. Ges. Nat. Fr. Berl. 3 : 27.

1829. Didymium cinereum (Batsch) Fr., Syst. Myc. 3 : 126.

1829. Physarum plumbeum Fr., Syst. Myc. 3 : 142.

1845. Didymium scrobiculatum Berk., Hook. Lond. lour. Bot. 4 : 66.

1875. Physarum cinereum (Batsch) Pers. ex Rost., Mon. 102, in part.

1892. Physarum scrobiculatum (Berk.) Massee, Mon. 300.

Sporangia sessile, closely gregarious or heaped, subglobose, elongate
or plasmodiocarpous, more or less calcareous, lilaceous gray; peridium
simple, thin, more or less densely coated with lime; capillitium strongly
developed, the internodes more or less richly calcareous and badhami-
oid, the lime-knots rounded and angular; spore-mass purplish brown,

46 THE MYXOMYCETES

spores clear violaceous, distinctly warted, 7-11 ju. Plasmodium watery-
white or colorless.

This delicate species is well defined by the characters given. It
occurs not rarely on richly manured ground, in forests, meadows,
lawns or even on the open prairie. The Plasmodium may form rings
several inches in diameter, scattered here and there over a surface
several square feet in extent, in fruit ascending the blades of grass,
completely covering these with the crowded sporangia. The color of
the fruit is well described in the specific name; gray or ashen gray.
The spores are usually very distinctly papillate; in some specimens,
however, almost smooth; in a few instances, rough.

The present species well illustrates the difficulty confronting the
author of today who, discussing a group of microscopic organisms,
would fain use the nomenclature of his predecessors, honored, but
equipped with insufficient lenses. Here is a species reported common
in Europe, observed by every mycologist there, from Micheli down,
and yet awaiting adequate description until Rostafinski in his great
book gives the results of microscopic analysis. We are now really
dealing with P. cinereum Rost.; P. cinereum (Batsch) is a compliment
to certain rather clever water-color drawings.

Rostafinski gives a long list of synonyms; none, it is believed, rep-
resent American forms; and without taking careful thought, surely
no one would rudely disturb such honorable interment, but in his
description the range of spore measurement, 7-13.3 yu, gives us pause,
and raises the suspicion that possibly, in one case or another, the
sepulture were perhaps premature. The range is too great! Perhaps,
in the series offered in confirmation, small-spored forms represent one
species, large-spored, something else. European students may decide
this at their leisure. But Rostafinski having, not without much labor,
practically completed his review of the physaroid forms, had almost
finished the last genus Badhamia, when his mind perhaps returned,
no doubt with some lingering misgivings, to the thirteenth species in
his Physarum list. There were there, he recalled, some large-spored
specimens which had rather badhamioid capillitium. The sessile
physarums of Fries were also before him, those especially, "floods
albis." Of these one shall be B. panicea, one B. lilacina and one
B. verna, described as having rather delicate colorless capillitial tubes
combined in a loose net, the calcareous deposits about the enlarged
intersections scanty, the spores 12.5 ju. The description of the fruc-
tification as a whole is a condensed statement of that which describes
P. vernum, and all taken together indicates some physarum. See
comment under P. vernum.

PHYSARUM 47

P. plumbeum Fr. belongs here. It has similar spores; the only
difference is a less calcareous peridium and more scattered habit of
fructification with more nearly regular, depressed-globose sporangia.
P. cinereum Pers. as cited by Link (Mag. Ges. Nat. Fr. Berl. 3 : 27,
1809) is apparently a badhamia, but may be P. vernum, while P. gri-
seum is probably the present species. Specimens collected by Wingate
and distributed by Ellis and Everhart as N. A. F. 2085, should be
referred to Didymium melanospermum.

Var. scintillans Brandza, Bull. Soc. Myc. Fr. 44 : 260, 1929, is de-
scribed as having isolated metallic blue or bronze sporangia with few or
no calcareous nodes. The bluish form is described as having spores
9-10 n, the bronze, 12-14 fx. Its position must be regarded as uncertain.

Careful examination of a wide range of American collections sug-
gests that the large-spored forms are not P. vernum and constitute a
distinct variety of P. cinereum, perhaps a closely allied species.

Common and cosmopolitan.

4. Physarum gilkeyanum Gilbert

Am. Jour. Bot. 19 : 133. 1932.

Sporangia gregarious, globose or clavate, sessile, but narrowed at
the base, 0.4 to 0.8 mm. in diameter, 0.7 to 0.9 mm. tall; peridium
hyaline, gray when without lime but usually covered with a thin even
layer of grayish white lime, brittle, breaking irregularly, the inner
surface rough, the lime covering forming a reticulation of thin wrinkles
over the entire sporangium; capillitium of fine hyaline threads, a
dense, rigid, fine-meshed net that retains the form of the sporangium
after the peridium breaks away, the lime-knots white, few, in the
upper part of the sporangium small and more or less rounded, in the
base of the sporangium tending to be long branching and somewhat
badhamioid with larger meshes in the capillitium; spores dark violet
in mass, globose, warted, violet-brown under the lens, 9-11 ix.

Oregon. In leaf mold under deciduous trees and brush.

5. Physarum megalosporum Macbride

N. A. Slime-Moulds ed. 2. 63. 1922.
1917. Physarum melanospermum Sturgis, Mycologia 9 : 323, non Pers.

Sporangia gregarious, sessile or short-stipitate, depressed, annulate,
or at least umbilicate above, white, rarely roseate, 0.5-0.8 mm. in
diameter; stipe, when present, short, thick, black or dark brown,
hypothallus none; columella none, but capillitium sometimes massed
toward the center; capillitium strongly calcareous, the delicate net
bearing an abundance of irregular white nodules; spores dark pur-

48 THE MYXOMYCETES

plish brown with a lighter area of dehiscence, minutely verruculose,

11.5-14.8 m-

This species is recognizable at once by its regular, uniform, de-
pressed, annulate or pitted sporangia, scattered evenly over the habitat
of rotten leaves or wood. In its form and habit it suggests a didymium.

Colorado.

6. Physarum sessile Brandza

Ann. Sc. Univ. Jassy 11 : 116. 1921.
1898. Physarum variabile Rex var. sessile List., Jour. Bot. 36 : 114, in part.

Sporangia solitary or gregarious, sessile, globose, 0.4-1 mm. in
diameter or forming elongated, sinuous plasmodio carps 2-10 mm. in
length and 0.5-0.8 mm. broad, grayish, bluish gray or pale gray;
peridium smooth, forming a fragile crust, formed by the aggregation
of transparent, calcareous granules 1 //. in diameter; pseudocolumella
globose, white; capillitium abundant, long-persistent, with rounded,
subequal, calcareous nodes 15-25 \x in diameter, formed of masses of
granules identical with those of the peridium, and which, like them,
become dissociated in water; connecting threads scanty, hyaline;
spores smooth, pale violaceous brown, 6-8 //. Plasmodium grayish
white.

As originally described this included both this species and P. aureum.
In a later paper (1929), the author clearly distinguishes between the
two species and the later description is here followed.

On dead leaves: West Indies; Rumania, Japan. The Lister mono-
graph records the species from Canada, Venezuela, Switzerland and
Ceylon. It is not certain whether the collections cited are this species
or P. aureum.

7. Physarum serpula Morgan

Jour. Cin. Soc. Nat. Hist. 19 : 29. 1896.
PI. Ill, Figs. 47, 48.

1892. Physarum gyrosum Rost. ex Massee, Mon. 307, in part.

1894. Badhamia decipiens (Curt.) Berk, ex Lister, Mycetozoa 32, in part.

Sporangia sessile, sometimes subglobose, usually forming plasmo-
diocarps in the form of lines, rings or a simple network, 0.3 mm. in
diameter; yellow or ochraceous, fading; peridium thin, fragile, simple,
membranaceous but persistent, borne on a rather widely effused
hypothallus; capillitium of numerous yellow lime-knots connected
by short and scanty hyaline threads; spores globose, violaceous by
transmitted light, minutely warted, 10-13 /x. Plasmodium at maturity
greenish yellow.

PHYSARUM 49

A very distinct species not likely to be confused with anything else.
In description, so far as concerns external characters, it suggests
Cienkowskia reticulata, but lacks the orange and red colors. The two
forms are not at all alike when placed side by side. For details as to
the difference, see the description of the species last mentioned.

In 1805, Albertini and Schweinitz (Consp. Fung. 90) described as
Physarum reticulatum a European form which became the basis of
Rostafinski's genus Cienkowskia. Later, in 1829, Schweinitz collected
in America a physarum-like specimen which he took to be the same
thing, and accordingly placed it in his herbarium under this name, and
listed it in his 1832 paper as No. 2295. Rostafinski further renamed
another Schweinitzian species, Fuligo muscorum, calling it (Mon. Ill)
Physarum gyrosum. Wingate and Rex apply in Ellis, N. A. F. 1396,
this latter name to No. 2295 of Schweinitz. Such a reference is a mis-
take, judging from Rostafinski's descriptions and from the descrip-
tions and figure of Albertini and Schweinitz (Consp. Fung. 86), and
by the testimony of Lister.

Eastern United States to Iowa and Nebraska, not rare; Japan.

8. Physarum aureum Brandza, non Pers. 1794

BuU. Soc. Myc. Fr. 44 : 261. 1929.

Sporangia solitary or in small groups, sessile, 0.4-0.6 mm. in di-
ameter or forming elongated, sinuous plasmodiocarps, 2-12 mm. long
by 0.4-0.6 mm. wide, bright yellow; peridium rugulose, pelliculose,
transparent yellow, encrusted with very minute yellow calcareous
granules clustered in small groups; columella lacking; capillitium well
developed, long-persistent, with firm, bright yellow calcareous nodes,
angular and of unequal sizes, ranging from 10-25 n, composed of very
minute calcareous granules similar to those on the peridium and not
breaking up in water; connecting threads numerous, hyaline, branched;
spores pale violaceous brown, minutely echinulate, 9-12 /jl. Plasmodium
bright yellow.

South Carolina, New York; Rumania.

9. Physarum virescens Ditmar

in Sturm, Deutsch. Fl. Pilze 1 : 123. 1817.
PI. Ill, Figs. 49, 50.

1818. Physarum thejoteum Fr., Symb. Gast. 21.

1832. Physarum ccespitosum Schw., Trans. Am. Phil. Soc. II. 4 : 258.

1873. Didymium nectriceforme Berk. & Curt., Grev. 2 : 65.

1876. Physarum ditmari Rost., Mon. App. 8.

1877. Didymium sinapinum Cooke, Myx. Gt. Brit. 33.

50 THE MYXOMYCETES

Sporangia small, 0.2-0.4 mm. in diameter, or rarely larger, sessile,
often crowded or heaped in small bunches, a dozen or more sporangia
in one pile, spherical, ovoid or elongate, yellow or greenish yellow or
pallid gray-green; peridium thin, fragile; capillitium delicate, with
rather small, irregular, yellowish, calcareous nodes; columella none;
spores bright violet, minutely roughened, 7-10 ix.

This species occurs most commonly on moss-tufts, with which it is
frequently concolorous, or escaped on dead leaves, etc. The peridium
is flecked with calcareous scales or grains stained yellow or green, and
to these the whole fruit owes its peculiar color. The color and aggregate,
heaped sporangia are distinctive macroscopic characters.

In the Monograph, p. 103, Rostafinski properly adopted Ditmar's
name for this species. Upon later consideration, in the Appendix, he
changed the name, writing P. ditmari, on the ground that virescens
was descriptive of a character to which it occasionally refuses to
conform. Most authors since Rostafinski have simply accepted his
suggestion, so that the species is often entered as P. ditmari Rost.
P. virescens is certainly to be preferred.

Var. obscurum List, is greenish gray, larger, with spores 6-8 /z; var.
nitens List, is bright yellow or orange.

Widely distributed in Canada, the United States and Europe; also
Java, Japan.

10. Physarum lateritium {Berk. &" Rav.) Morg.
Jour. Cin. Soc. Nat. Hist. 19 : 23. 1896.

1873. Didymium lateritium Berk. & Rav., Grev. 2 : 65.

1873. Didymium croceoflavum Berk. & Br., Jour. Linn. Soc. 14 : 84.

1876. Physarum ditmari var. croceoflavum Rost., Mon. App. 9.

1876. Physarum ditmari var. lateritium Rost., Mon. App. 9.

1879. Physarum inccquale Peck, Rept. N. Y. State Mus. 31 : 40.

1892. Physarum chrysotrichum Berk. & Curt, ex Massee, Mon. 300, in part.

Sporangia gregarious, sessile, globose, subglobose or plasmodio-
carpous, yellowish or orange when fresh, spotted with minute scarlet
granules; peridium thin, more or less rugulose; columella none; cap-
illitium delicate, the colorless or yellow threads connecting the yellow
nodules, these often with red centers; spores violet-brown in mass,
by transmitted light pale violet, minutely roughened, 7-9 lx.

A well-marked species easily recognized by the characters cited.
The extent of lime deposit at the capillitial nodes varies; it is some-
times very scanty. This acounts for Berkeley's generic reference.
The capillitium in broken specimens soon fades, becoming pallid or
whitish.

PHYSARUM 51

Nova Scotia and New York to Colorado and south, Brazil, Chile;
Europe, Ceylon, Malay Peninsula, Java.

11. Physarum rubiginosum Fr.

Symb. Gast. 21. 1817.
PI. IV, Figs. 51, 52.

1825. Leangium rubiginosum Fr., Stirp. Femsj. 83.
1829. Physarum fulvum Fr., Syst. Myc. 3 : 143.

Sporangia globose or cylindric, sessile or sometimes narrowed to a
stem-like base as if short-stipitate, 0.5-0.8 mm. in diameter, olivaceous
brown to reddish brown or scarlet; peridium simple, thin, rugulose
or plain, the calcareous scales few, or apparently included; columella
none; capillitium dense, the nodules rather large, angular, rusty brown;
spores dull violaceous, faintly warted, 9-11 ix. Plasmodium scarlet.

A beautiful, well-marked species, evidently rare in North America.

In the west there is a plasmodiocarpous form of the species. It has
the characteristic spores and capillitium but in form and habit differs
very decidedly. The fructification is a delicate netted plasmodiocarp,
the tubule about 0.5 mm. broad, bright red; peridium simple, carti-
laginous, dehiscent from above, and flecked with just here and there a
red calcareous scale. A collection from Ontario (Dearness) has spores
ranging from 11-12 fx, but probably belongs here.

New Hampshire, Ontario, Iowa, Colorado; Europe.

12. Physarum digitatum Farquh. & G. List.

Jour. Bot. 54 : 128. 1916.
PL IV, Figs. 53, 54.

1896. Physarum thejoteum Morgan, non Fr., Jour. Cin. Soc. Nat. Hist. 19 : 22.
1911. Physarum virescens Lister, non Ditmar, Mycetozoa ed. 2. 83.
1922. Physarum instratum Macbr., N. A. Slime-Moulds ed. 2. 62.

Sporangia subglobose, obovoid or cylindrical, very small, 0.1 to
0.3 mm. in diameter, closely crowded on a delicate hypothallus, often
connate, but not superimposed; dull orange, brownish or tawny;
peridium thin, covered with very minute, tawny calcareous scales;
columella none; capillitium lax, often scanty, the nodules small,
yellowish or brownish, occasionally confluent; spore-mass dull vio-
laceous, spores pale violet, with clusters of minute warts scattered
over the surface, 6-7 /a.

Not uncommon in the Mississippi valley, where it sometimes is
passed by the collector as an immature form of some other species.

52 THE MYXOMYCETES

The appearance is very characteristic, unlike P. virescens in habit,
size and color. Colonies are quite often three inches in length. The
most common habitat seems to be rotten oak, especially fragments of
charred logs, etc.
Ohio, Illinois, Iowa, Missouri, Nebraska; Nigeria, South Africa.

13. Physarum famintzini Rost.

Mon. 107. 1875.
1898. Physarum gulielmce Penzig, Myx. Buit. 34.

Sporangia sessile, subglobose or reniform, about 0.4 mm. in width,
brownish orange or chestnut brown, rugulose, clustered or heaped,
often with a yellow membranous hypothallus; peridium membranous,
with clustered deposits of yellowish brown lime granules; capillitium
abundant, the nodes angular, branching, white; spores purplish brown,
spinulose, 10-12 /jl. Plasmodium yellow or orange.

This is an old-world species. In the United States National Herba-
rium there is a scanty collection from Maryland (No. 15976), consist-
ing of five sporangia, growing with Didymium squamulosum, which
must be referred here. The hypothallus is brilliant orange, the spores
purplish, 9-11 m, averaging 9.5/*, a little small for the species as
described. In other respects the agreement is perfect.

Maryland ; Europe, Java.

14. Physarum confertum Macbr.

N. A. Slime-Moulds ed. 2. 64. 1922.
PL XXI, Fig. 560.

1896. Physarum atrum Schw. ex Morg., Jour. Cin. Soc. Nat. Hist. 19 : 27,
non Schw.

Sporangia subglobose or somewhat elongate, sessile, small, 0.2-
0.4 mm. in diameter, gregarious or confluent, often clustered or in
heaps, dull violaceous brown; peridium thin, more or less transparent,
nearly limeless, or reticulated or sprinkled with minute white flecks of
lime; capillitium scanty, the nodes small, elongate, rounded, white;
columella none, spores violet-brown, minutely warted, 10.5-12.5 ju.
Plasmodium white or yellowish.

Following Morgan, this has frequently been referred to as P. atrum
Schw. The latter species is now known to be a limeless form of P. di-
dermoides. P. reticulatum Berl., in Saccardo, Syll. Fung. 7:350, 1888,
non Alb. & Schw., is based on P. atrum Schw. The species has also
been confused with P. cinereum, P. plumbeum and others, but it is in
fact quite distinct, distinguished from everything else by the color and

PHYSARUM 53

small size of the heaped sporangia. It resembles some phases of
P. virescens where the sporangia are small and somewhat heaped or
rather aggregated, and scantily supplied with lime; but in such case the
lime is yellow and the spores are small.
Not uncommon, especially eastward; occurring also in Europe.

15. Physarum lepidoedeum Gilbert

Am. Jour. Bot. 19 : 133. 1932.

Sporangia sessile, solitary or in small groups, on black waste matter
forming a small hypothallus, irregularly globose, 0.5 to 1.2 mm. in
diameter, with a tendency to form small crowded plasmodiocarps;
peridium blue-gray, membranous, iridescent, with a thin layer of flat,
more or less rounded lime-scales similar to those of Lepidoderma;
capillitium a dense net of colorless threads, the lime-knots white, con-
spicuous but not abundant, medium sized, rounded or with points
meeting the capillitial threads, a few sometimes larger and more
angled; spores dark purple in mass, globose, under the lens bright
violet, uniformly finely warted, 12-14 ix in diameter.

The Lepidoderma-like peridium is distinctive. The spores are larger
than in most physarums and very uniform in size.

Oregon : on old kale stalks in a pile of herbaceous waste.

16. Physarum nudum Macbride

Am. Jour. Bot. 19 : 134. 1932.

Sporangia sessile, globose or somewhat plasmodiocarpous, occa-
sionally with a pallid, slender, usually prostrate stipe, 0.4-0.7 mm. in
width; peridium single, limeless, dark gray, somewhat iridescent;
hypothallus scanty, reticulate, membranous, hyaline, connecting the
lines of sporangia; columella none; capillitium sparse and nearly or
quite limeless, composed of slender thread-like tubules here and there
expanded into hyaline vesicular structures; spores violet-black in mass,
clear violet under the lens, minutely roughened, 9.5-11 /x in diam-
eter.

A specimen collected by T. H. Macbride in Washington in 1916, was
marked as a new species under this name. Another specimen, collected
by Mr. H. C. Gilbert in May, 1930, near Salem, Oregon, proved to be
the same. In its limeless character it suggests P. confertum, but differs
in size, color and habit of growth; it suggests also limeless forms of
P. didermoides but is different in habit, and with smaller, lighter
colored, much smoother spores. Mr. Gilbert notes that the sporangia

54 THE MYXOMYCETES

are milk-white when young, which would indicate a watery or white
Plasmodium. Apparently the plasmodium remains in the soft rotting
wood, coming to the surface only at the time of fruiting.
Oregon, Washington.

16a. Physarum nasuense Emoto

Bot. Mag. Tokyo 45 : 551. 1932.

Sporangia scattered or grouped, sessile, elliptical, short-pulvinate or
branched, 0.35-0.5 mm. in width, Eugenia red * or jasper red *; wall
double, the outer membrane cartilaginous, scarlet *, the inner mem-
brane pale yellow, thin, transparent, bearing small calcium granules,
attached to the outer; hypothallus and columella lacking; capillitium
of thin, pale yellow, transparent threads and concolorous nodules with
deep red centers, the calcium granules of the nodes round, 1-3 ju in
diameter, the nodules irregular, angular or round; spores globose,
violet-brown, uniformly warted, 8-10 /*. Plasmodium orange-red.

Differing from P. lateritium in color, in regular dehiscence and in the
double wall, and from P. brunneolum in shape, color and capillitial
characters. In incompletely matured sporangia the wall is more cal-
careous and the dehiscence lobate. Non-calcareous sporangia occur
which are dark brownish or dark violet-brown. We have seen no
specimens.

Known only from Japan.

17. Physarum echinosporum Lister

Jour. Bot. 37 : 147. 1899.

Sporangia scattered, forming chalk-white, usually curved plas-
modiocarps, strongly compressed laterally, dehiscing along the thin
upper ridge; sporangium wall of two layers, the outer smooth, egg-
shell-like, charged with minute lime granules, separating from the
membranous iridescent pale purplish inner layer; capillitium of
numerous smooth white lime-knots of irregular shapes and sizes, con-
nected by short hyaline threads; spores purple, marked with strong
ridges and spines, 8 fx.

The above description is based on Lister, 3rd ed. We have not seen
authentic material. Obviously very close to P. bivalve, apparently
the chief distinctions being the firmer, smoother, outer peridium and
the very rough, ridged spores.

Known only from Antigua, West Indies.

* An asterisk after a color term indicates that it is used in the sense of Ridgway: Color
Standards and Nomenclature, 1912.

PHYSARUM 55

18. Physarum bivalve Pers.

Ust. Ann. Bot. 15: 5. 1795.
PI. IV, Figs. 57, 58, 59.

1791. Reticular ia sinuosa Bull., Champ. 94.

1828. Angioridium sinuosum (Bull.) Grev., Scot. Crypt. Fl. 310.

1829. Diderma valvatum Fr., Syst. Myc. 3 : 109.

1829. Physarum sinuosum (Bull.) Weinm. ex Fr., Syst. Myc. 3: 145, non Link.
1849. Carcerina valvata Fr., Summ. Veg. Scand. 451.
1869. Diderma contortum Fuck., Symb. Myc. 341.

Fructification plasmodiocarpous, the plasmodiocarp creeping in
long vein-like reticulations or curves, laterally compressed, or some-
times sporangiate, distinct and crowded, sessile; peridium double, the
outer layer thick, calcareous, fragile, snow-white to gray or yellowish,
the inner delicate, colorless, the dehiscence by more or less regular
longitudinal fissure; capillitium strongly developed with abundant
white, calcareous granules; spores minutely spinulose, dull violet,
8-10 ix. Plasmodium reported as pale gray, or nearly white, but typical
specimens are sometimes associated with a yellow Plasmodium.

Easily recognized at sight by its peculiar form, bilabiate and sinuous.
Except for its microscopic structure, perfectly described by Fries,
Syst. Myc. 3 : 145. Habitat various, but not infrequently the upper
surface of the leaves of living plants, a few inches from the ground.
Plasmodiocarpous and sporangiate fructifications often occur side by
side, or merge into one another from the same plasmodium. Where the
substratum affords room the plasmodiocarpous style prevails; in
narrower limits single sporangia stand. The calcareous deposit on the
peridium is usually very rich and under a lens appears made up of
countless snowy or creamy flakes. Forms occur, however, in which
these outer deposits are almost entirely wanting; the peridium becomes
transparent, the capillitium visible from without. Judging from mate-
rial before us, this appears to be the common presentation in western
Europe. The degree of compression is very variable. Some collections
show compressed plasmodiocarps opening by narrow fissure along their
knife-edged summit, with scarce place for capillitium at all between the
approaching walls; others take the form of colonies of sporangia almost
terete, calcareous without, opening in f ragmen tal fashion at the top,
displaying sometimes the thin membranous inner wall, but at length
fissured and gaping as in the more usual phase figured by various
authors, where the plasmodiocarp is simply compressed but not ex-
travagantly thin. Both types occur in the western mountains, forms
with and without calcium, fissured by wider or narrower cleft, from
the same plasmodium; forms bilabiate and forms opening at first to

56 THE MYXOMYCETES

display an inner peridium; forms globose with narrow base, but apex
cleft, and forms ellipsoidal, yet compressed, opening like the gaping of
some tiniest bivalve. Some of the shorter forms become obovate, the
bases so constricted as almost to constitute stipes. Surely variation in
the same plasmodium can go no farther !

Cosmopolitan. Widely distributed in the United States and often
common. Frequent in Europe and reported from all continents except
Australia. We have a collection, however, from Samoa.

19. Physarum bitectum List.

Mycetozoa ed. 2. 78. 1911.
PI. IV, Figs. 55, 56.

1891. Physarum diderma List., Jour. Bot. 29 : 260, non Rost.

Sporangia gregarious, some subglobose and sessile, mostly plasmo-
diocarpous, smooth, white or pallid, terete or somewhat compressed;
peridium double, the outer wall calcareous, free and deciduous above,
recurved and persistent below, the inner smooth, pale purplish, more
persistent; dehiscence more or less irregular beginning at the top;
capillitium of large white nodules connected by short hyaline tubes;
spores violaceous brown, spinulose, with a conspicuous smoother area,
10-12 ii.

Related to P. bivalve, but differing in the purplish inner wall, the
larger, rougher spores, and the less compressed fructifications. The
latter character is variable in both species.

Colorado and Montana to the Pacific coast, not rare, Venezuela;
Europe, South Africa, Australia.

20. Physarum diderma Rost.

Mon. 110. 1875.
PL IV, Figs. 60, 61.

1898. Physarum didermoides Rost. var. lividum Lister, Jour. Bot. 36 : 162.
1907. Physarum testaceum Sturgis, Colo. Coll. Pub. Sc. Ser. 12 : 18.

Sporangia snow-white, clustered, sessile or narrowly adnate, globose
or polygonal by mutual compression; peridium double, the outer layer
dense, fragile, thick, calcareous, the inner delicate, remote, translucent;
capillitium well developed, the calcareous nodules white, rounded or
angular, sometimes uniting to form a pseudocolumella; spore-mass
black; spores purplish, distinctly rough, 10-12 fx.

A beautiful and distinct species. As others in the group with which

PHYSARUM 57

it is here associated, it is a physarum with the outer seeming of a
diderma. It occurs in Europe, therefore it is safe to assume that
Rostafinski saw it. So well marked it is that any good description will
define it, and Rostafinski describes it perfectly, adequately.

Mr. Lister having used for another species the name we here apply — •
see under P. bitectum — referred this present form to P. didermoides
Rost. Professor Sturgis, convinced that such reference was at least
doubtful, gave to our American gatherings the distinctive name above,
citing specimens from Massachusetts, from Colorado, and from Cali-
fornia. Curiously enough he also includes specimens of P. didermoides
var. lividum List., sent from England.

As stated, Mr. Lister first applied the name P. diderma to a plasmo-
diocarpous form occurring in England and near P. bivalve. Later,
Mycetozoa, 2nd ed., 78, he adopted a new specific name, P. bitectum, for
the English specimens, and entered P. diderma as a probable synonym
for P. lividum Rost. There is really no more merit in this later com-
parison than in that discarded. The species P. diderma is not P. li-
vidum, but stands as originally delimited, and will, doubtless, again
appear in Europe.

Rare. Certainly rare in Europe and so far seldom seen in the United
States, though widely distributed. Specimens are before us from
Maine, New York, Ohio, Michigan, Iowa, Oregon. Reported from
Montana.

21. Physarum alpinum G. List.

Jour. Bot. 48 : 73. 1910.
PI. IV, Figs. 62, 63.

Sporangia globose and sessile, or plasmodiocarpous, dull yellow,
smooth or scaly; peridium double, the outer wall densely calcareous,
separating irregularly from the membranous inner wall; capillitium
densely calcareous, the nodes large, more or less branched, yellow;
spores purple-brown, closely and minutely warted, 9-14 n.

This species is based by its author upon a gathering made in Cali-
fornia by Dr. Harkness and named by Phillips, who received it in
England, Badhamia inaurata. He seems not to have described it.
Since its first appearance, the form has been found repeatedly in the
Juras, whence Meylan reports pale yellow or whitish forms with,
however, the typical yellow capillitium. Specimens from Mt. Rainier
are believed to be the same. The more strongly marked plasmodio-
carpous habit and yellow capillitium separate this from the related
P. contextum and P. mortoni.

California, Washington ; Europe.

58 THE MYXOMYCETES

22. Physarum conglomeratum Rost.

Mon. 108. 1875.

1886. Physarum ochraceum Schroet., Krypt.-Fl. Schles. 3 (1) : 130, non Diderma

ochraceum Hoffm. 1795.
1892. Physarum rostafinskii Mass., Mon. 301.

Sporangia depressed, globose or irregular, sessile, more or less ag-
gregated and often angular by mutual pressure, 0.3-0.5 mm. broad,
ochraceous yellow; peridium double, the outer thick, cartilaginous, at
length irregularly ruptured and reflexed, disclosing the more delicate,
ashen gray inner membrane which encloses capillitium and spores;
capillitium abundant, showing large, white irregular calcareous thick-
enings which are often consolidated and in some sporangia tend to
aggregate at the center forming a pseudocolumella ; spore-mass brown,
spores violaceous, slightly roughened, 8-10 /jl.

This beautiful species shows a peridium as distinctly double as in
any diderma. The outer peridium is reflexed exactly as in some
species of that genus; is yellow without, white within and withal long-
persistent. The capillitium of course distinguishes the species instantly
as a physarum. It is distinguished from P. contextum by the size of
the spores. This being a decisive specific character the synonymy
prior to Rostafinski is uncertain. The specific name adopted by the
Polish author is therefore approved, although perhaps not the earliest.

Rare in North America, but widely distributed there and in Europe ;
India.

23. Physarum contextum Pers.

Syn. Meth. Fung. 168. 1801.
PL VI, Figs. 101, 102.

1796. Diderma contextum Pers., Obs. Myc. 1 : 89.

1818. Didymium contextum Fr., Symb. Gast. 20.

1849. Leocarpus contextus Fr., Summ. Veg. Scand. 450.

1873. Diderma ochroleucum Berk. & Curt., Grev. 2 : 52.

1876. Diderma flavidum Pk., Rept. N. Y. State Mus. 28 : 54.

1892. Physarum conglomeratum Mass., Mon. 304, non Rost.

Sporangia distinct or subplasmodiocarpous, sessile, densely crowded,
oval, reniform or elongated, 0.3-0.6 mm. wide; peridium double, the
outer rather thick, calcareous, yellow or yellowish white, rarely pink-
ish buff, the inner thin, yellowish or pallid; capillitium white, con-
taining numerous large, irregular calcareous granules; columella none;
spores deep violet, distinctly and irregularly spinulose, 11-13 ix.

This singular species occurs not rarely upon the bark of fallen twigs,
upon bits of straw or grass stems lying undisturbed upon the ground.

PHYSARUM 59

In such a position the slime mold covers, as with a sheath, the entire
substratum. The outer peridium, especially its upper part, is entirely-
evanescent. Not rare in summer and autumn.

New England to Washington and Nicaragua, also West Indies;
Europe, India.

24. Physarum mortoni Macbr.

N. A. Slime-Moulds ed. 2. 58. 1922.
PL V, Figs. 72, 73.

1925. Physarum contextum Pers. var. mortoni G. List., Mycetozoa ed. 3. 60.

Sporangia gregarious, clustered but distinct, sessile or with short
stipe, 0.7-0.8 mm. in diameter, bright ochraceous yellow to pallid;
peridium double, the outer layer rough, breaking up into rather few
large deciduous scales, the inner whitish, ochraceous or olivaceous,
nodular-calcareous, both persisting below to form a distinct cup;
capillitium lax, the nodes white, large, angular; columella none; hy-
po thallus scanty, colorless; spores dark purplish brown, rather coarsely
warted, 11-13 fi.

A very distinct species, related, no doubt, to P. contextum, but
different in habit, character of peridium and with darker, more coarsely
warted spores. It is never crowded, is only rarely plasmodiocarpous
and the outer peridium is generally deciduous except at the base and
falls in flakes.

Colorado, Oregon, Washington.

25. Physarum brunneolum (Phill.) Mass.

Mon. 280. 1892.
1877. Diderma brunneolum Phillips, Grev. 5 : 114.

Sporangia scattered or gregarious, but not crowded, globose, tur-
binate or subdepressed, rarely plasmodiocarpous, 0.6-1.7 mm. in
diameter, sessile or with a short stipe; peridium double, thick, smooth
or polished, yellow-brown without, stellately dehiscent, the segments
reflexed, white within; stipe, when present, short, stout, rugose, lime-
less, red-brown; columella none, but pseudocolumella sometimes pres-
ent; capillitium dense, the nodes numerous, large, irregular, white,
the internodes thin, short, colorless; spores globose, lilac, clearly
echinulate, 8-10 \x (Lister), 6-7 n (Massee).

What seems to be an otherwise typical specimen has spores aver-
aging 12.5 ijl.

This form was first described by Phillips as a diderma. Later
students of the specimens preserved by Phillips agree that it is not a

60 THE MYXOMYCETES

diderma, but a craterium (Lister) or physarum (Massee). There
seems no reason why we should not respect the decision of Massee,
whose description is here quoted in somewhat abridged form. The
peridium is about as double as in many physarums, not more so;
the inner membrane so delicate as only occasionally to be revealed
except to searching scrutiny. But the appearance as a whole is as
of some brown diderma; only the calcareous capillitium abides to
prevent mistaken reference.

When opened by irregular dehiscence from above, the persisting
cup-like base of the sporangium recalls Leocarpus fragilis; but then
again the capillitium is different.

Rare but widely distributed. Colorado, Montana, California, Chile;
Europe, Australia.

26. Physarum ,eneum (List.) R. E. Fries

Arkiv Bot. 1 : 62. 1903.

Sporangia sessile, subglobose or forming simple plasmodiocarps
0.3-0.4 mm. in diameter, pinkish brown or bronze, glossy; peridium
double, the outer somewhat cartilaginous, brittle, falling back from
the shining, membranous inner wall; capillitium dense, the nodules
not large, brown, sometimes aggregated to form a pseudocolumella ;
spores pale brownish violet, nearly smooth, 6-8 /a.

Reported from West Indies, Bolivia; India.

27. Physarum bogoriense Racib.

Hedwigia 37 : 52. 1898.

1873. Diderma pallidum Berk. & Curt., Grev. 2 : 52, without description.
1898. Physarum pallidum (B. & C.) Lister, Jour. Bot. 36 : 117.

Sporangia sessile, subglobose, oval or forming elongate but not
reticulate plasmodiocarps, semicircular in transverse section; peridium
double, the outer thick, smooth, yellow or brown on the outside, white
inside, dehiscing in stellate fashion into persistent, more or less tri-
angular, reflexed lobes, remote from the thin, colorless or somewhat
iridescent inner wall; capillitium consisting of numerous large white
smooth-walled rounded and branching lime-knots connected by slender
hyaline threads; spores bright violet, "nearly smooth" or covered
with rather coarse warts, 7.5-8.5 /*, sometimes up to 10 p.

A distinct species, marked by its diderma-like, brown, distant outer
coat, with lobed or stellate dehiscence, and semicircular or somewhat

PHYSARUM 61

depressed cross section. Perfectly normal spores in some sporangia
range from 8.5-10 /jl.

Brandza (1929) reports this species as occurring under two aspects
in Moldavia, one form with simple, pallid sporangia, strongly com-
pressed laterally, the other plasmodiocarpous and chamois colored.
The former suggests certain aspects of P. bivalve.

Widely distributed in tropical and warm temperate climates in both
hemispheres. Less common in cooler regions but reported from New
York, California, Colorado and Pennsylvania.

28. Physarum penetrale Rex

Proc. Ac. Nat. Sc. Phila. 1891 : 389.
PI. IV, Figs. 65, 66, 67.

1896. Cytidium penetrate (Rex) Morgan, Jour. Cin. Soc. Nat. Hist. 19 : 11.

Sporangia scattered, stipitate, erect or nodding, ellipsoidal or pyri-
form, 0.4-0.6 X 0.3-0.4 mm., rarely globose; peridium greenish gray
or yellowish green, studded sparsely with rounded, pale yellow or
yellow-gray lime granules, rupturing to the base into two or four
segments; stipe variable, slender, subulate, rugulose, flattened later-
ally toward the base, translucent, dull red or golden red in color;
columella four-fifths the height of the sporangium, concolorous with
the stipe, acuminate; capillitium dense, persistent, the nodes frequently
calcareous, rounded, yellow; spore-mass brown, spores nearly smooth,
brownish, 6-7 //.

Readily recognizable by the elongate sporangia and the lengthened
columella. The capillitial nodes are at first pale yellow, but tend to
whiten on exposure. The spores when highly magnified show delicate
spinulescence.

Cosmopolitan. Not common in North America. A specimen in the
Ellis collection, New York, from Dr. Rex, is labelled P. columelliferum
but this name seems not to have been published.

29. Physarum puniceum Emoto

Bot. Mag. Tokyo 45 : 229. 1931.

Sporangia clustered, cylindrical, stalked, bright pink, 0.5-1 mm.
tall, 0.4-0.5 mm. broad; stalk up to 0.15 mm. tall and 0.05 mm. thick,
sometimes almost lacking, bright purple-red, longitudinally striate;
peridium thin, membranous, bright rose, encrusted with small round
crystals 1 n in diameter; hypothallus round, concolorous with the
stalk; columella always present, conspicuous, bright pink, stout, cy-

62 THE MYXOMYCETES

lindrical, 0.1 mm. thick, almost reaching the top of the sporangium
and remaining after the breaking away of the sporangium wall;
capillitium delicate, the threads almost colorless, with enlarged ends,
the nodes white, few, of various forms and sizes, filled with small round
crystals 1 /jl in diameter; spores spherical, violet-brown, thickly covered
with flat warts, 6-8 jit.

Distinguished by the color, the stalk, the columella, the delicate
capillitium and the size of the spores.

Known only from southern Manchuria, on living leaves.

30. Physarum crateriforme Petch

Ann. R. Gard. Perad. 4 : 304. 1909.

Sporangia gregarious or solitary, grayish white or pale brown,
globose, clavate or crateriform, 0.4-0.6 mm. in diameter, stipitate or
sometimes sessile, 1-2 mm. in total height; stalk when present opaque,
conical, black, or black below and white above; columella cylindrical,
often reaching the apex of the sporangium, or shorter, then clavate
or conical, concolorous with the stipe or paler, occasionally lacking;
capillitium various, strongly calcareous, the nodules either massed
about the columella, or, in the globose sporangia, rod-like and ascend-
ing; spores closely spinulose, 10-13 /x.

Iowa, Antigua; western Europe, West Africa, Ceylon, Japan.

31. Physarum listeri Macbr. nom. nov.

PL V, Figs. 74, 75.
1904. Physarum luteo-album List., Jour. Bot. 42 : 130, non Schum.

Sporangia gregarious, subglobose, large, about 1 mm. in diameter,
yellow, shading into white, orange or olivaceous, smooth or rugulose,
stipitate; stipe stout, smooth, 0.5-1 mm. high, yellow or orange above,
white below, cylindric, lime-stuffed; columella large, subglobose or
clavate, yellow; capillitium either of very slender pale yellow threads,
branching at acute angles and anastomosing, or of broad, yellow, sim-
ple or forked strands, persistent after spore dispersal; nodules few,
small, linear or fusiform; spores purple-brown, coarsely and somewhat
irregularly spinulose, 10-13 /jl. Plasmodium orange.

The general plan of structure corresponds very well with Fries'
idea of his genus Tilmadoche, although the present species would
seem, by very grossness, strangely out of place with the tilmadoches.
But the singular didermoid, evenly branching threads of the capil-
litium bearing their slender spindle-shaped burdens of lime are very

PHYSARUM 63

suggestive; it is a diderma gone wandering into the camp of the physa-
rums if one may judge from Miss Lister's graphic plate.

The name given to this species by Mr. Lister is antedated by over a
century. Schumacher (Enum. PI. Saell. 2 : 199. 1803) gave the name to
what Fries thought was a perichaena; at any rate not a physarum.
Fries makes Schumacher's combination a synonym for Perichana
quercina Fr., which Rostafinski in turn makes synonymous with
Perichana corticalis (Batsch) Rost. According to the International
Rules as revised at Cambridge, the name Physarum luteo-album cannot
be revived even though the earlier name is universally regarded as
non-valid. A new name must, therefore, be applied, and we suggest
listeri, as suggested in N. A. Slime-Moulds, 2nd ed., p. 71.

Var. aureum Ronn, as distributed by Jaap, No. 84, does not seem to
differ from the typical form sufficiently to justify its recognition.

Colorado; Europe, India.

32. Physarum perfectum M. E. Peck

Am. Jour. Bot. 19 : 134. 1932.

Sporangia loosely gregarious, grayish white, globose, stipitate,
0.6-0.8 mm. in diameter; hypothallus very thin, colorless, wide spread-
ing; stipe yellowish white, stout, calcareous, nearly smooth, slightly
narrowed upward, equalling or a little surpassing the diameter of the
sporangium; columella well developed, white, conical, nearly one-third
the height of the sporangium; peridium a thin membrane, evenly
granular with included lime and thickly sprinkled with round, mainly
superficial, white scales of lime; capillitium moderately dense with
abundant, rounded and elongated, pale yellowish, calcareous nodes;
spores minutely roughened, violaceous brown, 10-11 (x.

Seemingly a well-marked species, having a trim, finished appearance.
Two or three colonies have been found in the neighborhood of Salem,
Oregon. The most striking structural feature is the stipe. Other fea-
tures suggest P. melleum (Berk. & Br.) Mass., but the color and greater
size at once distinguish it.

Oregon: on decaying bark of Populus sp.

33. Physarum globuliferum (Bull.) Pers.

Syn. Meth. Fung. 175. 1801.
PI. V, Figs. 76, 77, 78.

1791. Spharocarpus globulifer BuR., Champ. 134.

1791. Stemonitis globulifera (Bull.) Gmel, Syst. Nat. 2 : 1469.

1805. Trichia globulifera (Bull.) DC, Fl. Fr. 2 : 253.

64 THE MYXOMYCETES

1829. Diderma globuliferum (Bull.) Fr., Syst. Myc. 3 : 100.

1876. Physarum petersii Berk. & Curt. var. farlowii Rost., Mori. App. 6.

1876. Didymium subroseum Pk., Rept. N. Y. State Mus. 28 : 54.

1878. Physarum albicans Pk., Rept. N. Y. State Mus. 30 : 50.

1893. Physarum columbinum Macbr., Bull. Lab. Nat. Hist. Iowa 2 : 384, non

Pers.
1896. Cytidium globuliferum (Bull.) Morg., Jour. Cin. Soc. Nat. Hist.

19 : 10.
1896. Physarum relatum Morg., Jour. Cin. Soc. Nat. Hist. 19 : 26.

Sporangia gregarious, stipitate, globose or slightly depressed above,
about 0.5 mm. in diameter, pale blue-gray to pure white or sometimes
rosaceous; stipe calcareous, extremely brittle, at least equal to the
sporangium, usually longer, slender, slightly wrinkled, white, pallid
or yellow, when long tapering upward; columella white, conical, some-
times obsolete; hypothallus scanty, inconspicuous; capillitium dense,
but delicate, persistent, a close network of hyaline threads, with white
or yellowish nodes sparingly thickened and calcareous, many without
lime; spore-mass brown; spores violet by transmitted light, minutely
warted, the warts in indistinct clusters, 7.5-9 ju. Plasmodium yellow
or greenish yellow according to published records. We have a collec-
tion (S. U. I. 1485), typical in every respect, which developed from a
pale violet Plasmodium, without a trace of yellow.

This species, very common eastward, is at once very beautiful and
very variable. Its several phases have been again and again observed
and described too often by distinct specific or varietal names. A
form from New York, with long, white stems and almost pure white
sporangia, is P. albicans Peck. Forms occur like P. albicans, but flushed
with rose throughout. From New England, specimens sent Rosta-
finski were by him deemed a variety of P. petersii Berk. & Curt., and
called P. petersii var. farlowii Rost. By this name the species has been
generally distributed in this country. Most gatherings of this species
have small, somewhat ochraceous sporangia, and pale yellow, or some-
what rusty stipes. These latter, with somewhat heavier stem, represent
Physarum simile Rost. A form collected sparingly in Iowa has short,
white stipes and blue-gray sporangia one-third larger than observed
in the eastern types. This was recorded as P. columbinum Macbr., a
name already in use. The spores in the Iowa specimens are also a little
larger, 8-10 (x. Pale cyanic and roseate forms also sometimes occur
in late fruitings.

In all phases the persistent tenacity of the capillitium is a striking
characteristic well noticed by Fries (Syst. Myc. 3 : 101): "Peridia a
gleba omnino libera, dein tota diffracta, evanescentia, . . . capillitio
compacto forma servata persistente." The peridium, except a small

PHYSARUM 65

part below, all falls away, leaving the capillitium apparently intact,
crowded with spores.

Canada south to Mexico; apparently, in one form or another, cos-
mopolitan.

Var. confluens Brandza, Bull. Soc. Myc. Fr. 44 : 255, 1929, has ses-
sile or plasmodiocarpous, densely aggregated sporangia.

34. Physarum murinum List.

Mycetozoa 41. 1894.
PI. V, Figs. 79, 80.

1891. Physarum braunianum Lister, Jour. Bot. 29 : 259, non Rost.

1896. Cytidium ravenelii (B. & C.) Morgan, Jour. Cin. Soc. Nat. Hist. 19 : 10.
1899. Physarum ravenelii (B. & C.) Massee ex Macbr., N. A. Slime-Moulds 48.
1923. Physarum heterosporum Widder, Verb.. Zool.-Bot. Ges. Wien 73 : 159.

Sporangia scattered, globose or perfectly spherical, ashy brown,
rugulose, stipitate; stipe elongate, pale brown, erect, generally taper-
ing upward, calcareous, brittle; hypothallus none; columella short,
hemispherical or bluntly conical; capillitium dense, much as in P. globu-
liferum, the calcareous nodules umber, brownish or orange-yellow,
small; spore-mass brown; spores by transmitted light bright lilac,
finely warted, the warts somewhat clustered, 8-11 ix.

A very distinct species, easily known by its peculiar drab colored
peridium and dull brown stalks. The author of the species allows for
the capillitial nodes no other tint but brown. Under direct illumination
many gatherings, especially where the sporangia are well blown out,
show nodules of a bright orange tint.

Morgan regarded his Cytidium ravenelii as the same as Berkeley
and Curtis' Didymium ravenelii. Lister, however, finds that the type
of the latter species is referable to P. pulcherripes Pk. Morgan's de-
scription seems to refer to the present species rather than to pulcher-
ripes and his name is therefore retained in the synonymy.

Not rare in the eastern United States, to Missouri and Iowa, also
Washington; western Europe.

35. Physarum melleum (Berk. & Br.) Massee

Mon. 278. 1892.
PI. IV, Figs. 68, 69, 70, 71.
1873. Didymium melleum Berk. & Br., Jour. Linn. Soc. 14 : 83.
1873. Didymium chrysopeplum Berk & Curt., Grev. 2 : 53.
1876. Physarum schumacheri Spreng. var. melleum Rost., Mon. App. 7.

1892. Physarum kalchbrenneri Massee, Mon. 297.

1896. Cytidium melleum (Berk. & Br.) Morgan, Jour. Cin. Soc. Nat. Hist. 19:11.

Sporangia scattered, stipitate, globose, somewhat flattened below,
0.4-0.5 mm. in diameter, wall rugose, clear yellow or honey colored;

66 THE MYXOMYCETES

stipe conical, short, about equal to the sporangium, somewhat wrin-
kled, white or yellow; sometimes tawny; columella small but distinct,
concolorous with the stipe; hypothallus white, scanty, often lacking;
capillitium abundant, snow-white, with rather large angularly stellate
nodes; spores pale violet by transmitted light, almost smooth, 7.5-10 ju.
Plasmodium yellow.

Easily distinguished by its pale stipe and columella and white capil-
litium in contrast with the yellow peridial walls. N. A. F. 1395 is this
species. Massee refers it erroneously to P. schumacheri Spreng. The
description and specimen do not correspond. By that name the species
has, however, been hitherto known in the United States. In culture
brilliant orange sclerotia are formed on a white, strand-like hypothal-
lus.

Common in the eastern United States, rare west of the Mississippi,
Puerto Rico, Brazil, Bolivia; world-wide.

36. Physarum citrinum Schum.

Enum. PL Sail. 2 : 201. 1803.

1818. Physarum compactum Ehr., Sylv. Myc. Berol. 26.

1827. Physarum schumacheri Spreng., Syst. Veg. 4 : 528.

1829. Diderma citrinum (Schum.) Fr., Syst. Myc. 3 : 100.

1846. Physarum aureum var. chrysopus Lev., Ann. Sc. Nat. Bot. 3 ser. 15 : 166.

1876. Physarum leveillei Rost, Mon. App. 7, in part.

1896. Cytidium citrinum (Schum.) Morg., Jour. Cin. Soc. Nat. Hist. 19 : 9.

Sporangia gregarious, scattered, globose, 0.4-0.7 mm. in diameter,
somewhat flattened below, pale yellow, citrine, stipitate or nearly
sessile; peridium thin, covered almost completely with small calcareous
scales; stipe stout, erect, fragile, tapering upwards, furrowed, yellow,
opaque, arising from a small hypothallus which is sometimes continu-
ous from one sporangium to the next; columella small, conical, yellow;
capillitium a rather dense, delicate network, the calcareous nodules
yellow, numerous, roundish, and generally small; spore -mass black;
spores under the lens violaceous, almost smooth, about 8-10 /x.

This species seems to be rare in the United States. It somewhat
resembles P. melleum, from which it is distinguished by its brighter
color and yellow nodes, and its denser capillitium. P. galbeum is a
smaller form, and lacks the columella. Rostafinski strangely confused
the synonymy.

Var. sessile Meylan is reported from Switzerland and Rumania. In
our material it seems to merge into the typical form.

New England, Ohio, Colorado, Washington, South America;
Europe, South Africa, Australia.

PHYSARUM 67

37. Physarum pulcherrtpes Peck

Bull. Buff. Soc. Nat. Hist. 1 : 64. 1873.
PL V, Figs. 81, 82.

1873. Didymium erythrinum Berk., Grev. 2 : 52.

1873. Didymium ravenelii Berk. & Curt., Grev. 2 : 53.

1873. Physarum petersii Berk. & Curt., Grev. 2 : 66.

1875. Physarum schumacheri Spr. var. rufipes A. & S. ex Rost, Mon. 99.

1876. Physarum psittacinum Ditm. var. ravenelii Rost., Mon. App. 8.
1888. Physarum pulchripes Berl., Sacc. Syll. Fung. 7 : 349.

1896. Cytidium rufipes (A. & S.) Morg., Jour. Cin. Soc. Nat. Hist. 19 : 9.
1899. Physarum rufipes (A. & S.) Macbr., N. A. Slime-Moulds 50.

Sporangia globose, 0.5-0.7 mm. in diameter, yellow-orange to
tawny brown with lime deposits, dark iridescent beneath, the walls
thin, deciduous; stipitate, the stipe slender, erect, deep red, sometimes
black below, pale or orange above, and supported on a well-developed
hypothallus; columella small, conical or subglobose; capillitium dense,
the meshes and nodes unusually small and delicate, the latter reddish
or yellow; spore-mass dark violaceous gray; spores by transmitted
light pallid, faintly warted with clusters of darker warts, violet, 8-10 \i.
Plasmodium probably yellow.

The striking contrast of color between sporangia and stipes renders
this species at sight quite distinct from any related form. The peridia
in the specimens before us are black or iridescent sprinkled more or less
profusely with orange lime granules which sometimes cover all but the
base. The stipe, springing from a small hypothallus, is dark red below
for about one-fourth its height, then vermilion, above expanding
slightly beneath the peridium. The capillitium is a delicate net, with
numerous small, uniformly regular, orange, calcareous nodes.

This species is no doubt related to P. psittacinum. It is, however,
much smaller, has a calcareous stipe, and a much less variegated
peridium, and generally a small columella. It is also akin to P. glo-
buliferum and to P. murinum.

Eastern United States, Washington; not common. Reported from
Ireland.

38. Physarum pulcherrimum Berk.&Rav.

Grev. 2 : 65. 1873.
PI. V, Figs. 83, 84.

1873. Stemonitis porphyra Berk. & Curt., Grev. 2 : 69.
1879. Physarum atrorubrum Pk., Rept. N. Y. State Mus. 31 : 40.
1896. Cytidium pulcherrimum (B. & R.) Morgan, Jour. Cin. Soc. Nat. Hist.
19:8.

68 THE MYXOMYCETES

Sporangia scattered or gregarious, globose, even, or somewhat
wrinkled, dark red, reddish violet or purple, stipitate; stipe cylindric,
even, subconcolorous or blackish; columella small or none; capillitium
free from spores, whitish, with a slight pinkish tinge; spores dark brown
in mass, dark red when separated, globose, smooth, 7.5-8.5 /z. Plasmo-
dium dark red.

The capillitium is very delicate, and when cleared of spores the
knot-like thickenings are seen to be very small and of a dark red color,
to which is probably due the pinkish tinge which marks the whole. A
part only of the thickenings are filled with lime granules. The dark red
granules of the sporangium walls are abundant and appear to form a
continuous crust.

This is P. atrorubrum Peck, and his description has been closely
followed. The very brief description in Grevillea, however, antedates
the New York publication and, all inadequate as it is, no doubt applies
to the same thing.

Not rare. Eastern and central United States and Canada, Washing-
ton; Rumania, Ceylon, Malay Peninsula.

39. Physarum lilacinum Sturgis & Bilgram, non Fr. 1829

Mycologia 9 : 324. 1917.

Sporangia gregarious, stalked, globose, erect, pale lilac to pale
Indian-red in color, 0.5 mm. in diameter; sporangium wall mem-
branous, beset with rounded masses of lilac or reddish lime; stipe erect,
broad-based, tapering upwards, calcareous, furrowed, paler than the
sporangium or concolorous, 0.7-0.9 mm. long, about 0.1 mm. thick;
columella conical or columnar; capillitium delicate, rigid, persistent;
lime-knots small, rounded, composed of large, pale lilac or reddish,
spherical granules. Spores pale brown, almost smooth, 7-8 (x.

Miss Lister records as var. cceruleum (Mycetozoa, 3rd ed., 30) a form
with pale blue sporangium, lime-knots and stalk, collected with the
typical form.

Reported thus far only from Philadelphia.

40. Physarum nucleatum Rex

Proc. Ac. Nat. Sc. Phila. 1891:389.
PL V, Figs. 85, 86, 87.

Sporangia gregarious, spherical, 0.5 mm. in diameter, white, stip-
itate; peridial wall membranaceous, rupturing irregularly, thickly
studded with rounded white lime granules; stipe about 1 mm., subu-
late, yellowish white, rugose; columella none; capillitium dense, snow-

PHYSARUM 69

white, with minute, white, round or rounded nodes, in the center a
conspicuous mass of lime forming a shining ball, not part of the stipe
although sometimes produced toward it; spore-mass black; spores
brown-violet, delicately spinulose, 6-7 p.

This species most nearly resembles in appearance and habit of growth
P. globuliferum Pers., but may be distinguished from it by the absence
of a columella, by the central ball of lime, and the very small rounded
lime granules in the meshes of the capillitium. Exceptionally the lime
granules of the sporangium wall are sparse or absent entirely, in which
case the wall has a silvery or coppery metallic luster.

Var. robustum G. Lister (Jour. Bot. 64 : 226, 1926) is larger, with a
very short stipe and a blue or coppery, iridescent peridium.

New York, Pennsylvania, Maryland, Wisconsin, Iowa, Nicaragua;
Europe, South Africa, Japan ; the tropics generally.

41. Physarum wingatense Macbr.

N. A. Slime-Moulds ed. 2. 72. 1922.
PI. V, Figs. 91, 92.

1876. Tiltnadoche columbina Rost., Mon. App. 13.

1889. Tiltnadoche compacta Wing., Proc. Acad. Nat. Sc. Phila. 48.

1892. Didymium barteri Massee, Mon. 231.

1892. Lepidoderma stellatum Massee, Mon. 252.

1894. Physarum compactum (Wing.) List., Mycetozoa 44.

1916. Physarum columbinum (Rost.) Sturgis, Mycologia 8 : 200.

Sporangia gregarious or somewhat crowded, stipitate, erect or
cernuous, gray, brownish gray or bronze, globose; peridium thin,
metallic brown or bronze in color, splitting at maturity in floriform
manner into six to twelve segments; stipe limy, white or yellowish,
often shading to black or fuscous below, rather long, tapering upward;
hypothallus none; columella none; capillitium extremely delicate,
white or colorless, usually radiating from a central lime-mass or nucleus,
and with ordinary nodules small and few, fusiform; spore-mass brown;
spores by transmitted light violet-brown, delicately warted, 7-9 /z.
Plasmodium light gray.

This species is well marked by several characteristics; the brilliant
wall of the peridium, white-flecked and laciniate, the delicate didym-
ium-like capillitium running from center to peridium, and especially
the peculiar aggregation of Ume at the center of the sporangium, like
nothing else except a similar structure found in Physarum nucleatum
Rex. The variations affect the stipe and the distribution of the capil-
litial lime. Some eastern specimens show stipes black below; specimens
from Ohio and Nicaragua show stipes milk-white throughout. As to

70 THE MYXOMYCETES

the capillitium, in some of the Nicaragua collections the lime is more
uniformly distributed through the capillitium, and accordingly the
nucleus is not conspicuous, its place being taken by two or three nodes
plainly larger than the others. The peculiar brown metallic luster of the
peridial wall and the strongly developed calcareous patches with which
the peridium is covered are fairly constant features. RostafLnski called
it a tilmadoche, with which group it might easily be placed. The
capillitium is, however, distinctly netted.

The name Didymium columbinum Berk. & Curt, was never pub-
lished, although fragmentary remains under this name exist in both
the Berkeley and the Curtis herbaria. Rostafinski based his Tilma-
doche on Berkeley's specimen, and Miss Lister, who has examined it,
believes it is the same as Tilmadoche compacta Wingate. This is con-
firmed by Sturgis, after an examination of the material in the Curtis
herbarium. Physarum columbinum Pers. is universally recognized as
having been applied to Lamproderma columbinum; Physarum colum-
binum Somm. may have been the same thing although Fries regards it
as distinct from the form he cites as columbinum. His description,
however, strongly suggests a lamproderma. But whatever they may
be, the name cannot again be used. Massee's names are cited on the
authority of Lister. One or the other may eventually have to be
adopted. For the present, wingatense will serve to designate the species
as it occurs in North America.

North and South America and West Indies; Africa, southern Asia,
Malay Peninsula, Japan.

42. Physarum didermoides {Ach.) Rost.

Mon. 97. 1875.
PL V, Figs. 88, 89, 90.

1801. Spumaria ? didermoides Acharius, in Pers. Syn. Fung. Add. xxix.

1803. Diderma oblongum Schum., Enum. PI. Saell. 2 : 197.

1832. Physarum atrum Schw., Trans. Am. Phil. Soc, II. 4 : 257.

1832. Spumaria licheniformis Schw., Trans. Am. Phil. Soc. II. 4 : 261.

1849. Claustria didermoides (Ach.) Fr., Summ. Veg. Scand. 2 : 451.

1850. Didymium congestum Berk. & Br., Ann. Mag. Nat. Hist. 2 ser. 5 : 365.
1875. Physarum lividum Rost., Mon. 95.

1875. Physarum lividum Rost., var. licheniforme Rost., Mon. 96.

1882. Physarum cinereum (Batsch) Pers. var. ovoideum Sacc, Michelia 2 : 334.

Sporangia crowded, ovoid or cylindric, 0.4-0.6 mm. broad, stipitate
or sessile, blue-gray, often capped with white; stipe variable in length
and structure, where well developed pure white, often flattened, ex-
panded and diaphanous, connate with others through the irregular,
reticulate or sheet-like hypothallus; columella none; capillitium ample,

PHYSARUM 71

the lime-knots angular or rounded, white, connected by hyaline
threads; spores in mass black, by transmitted light dark violet, densely
spinulose, 12-15 //. Plasmodium watery white or gray.

A very variable species in many particulars. The sporangia in the
same cluster are stipitate and sessile, ovoid and spherical. Our descrip-
tion does not quite agree with that of Rostafinski; it is the outer
peridium that is with us white, burdened with lime; the inner is simpler
and comparatively thin. The whiteness of the outer peridium is, how-
ever, easily displaced. The colony may not show it at all, in which case
the peridia remaining give to the entire fructification a pale lead color,
very characteristic. The disposition of the lime in the capillitium is
also notably variable. Specimens occur which suggest Rostafinski's
Crateriachea; that is, the lime is massed as a snow-white pseudo-
columella in the center of each sporangium. In such cases the lime of
the outer peridium may be scanty or limited in amount, not forming a
calcareous cap. The size of the spores is also variable. Rostafinski
gives 12.5-14.2 n; not infrequently a single spore reaches 16 n, a very
unusual range of variation.

The species is fairly common in the upper Mississippi valley, and
can be obtained in quantity where once it appears, as the plasmodia
are profuse.

Physarum lividum Rost. (Mon. 95) is but a less calcareous form of
this, as is evident even by the author's description. Professor Morgan
thought P. lividum a phase of P. griseum Lk. Link, however, reckons
P. griseum the same as P. cinereum.

Forms without a stipe, with thinner sporangium wall and with
spores paler and smoother on one side are segregated as the var. lividum
Lister in the English monograph.

Eastern North America to Kansas, Washington, Nicaragua. Es-
pecially to be looked for on the bark of fallen stems of Populus and
Negundo. Also South America; Europe, Asia, Africa.

43. Physarum mutabile (Rost.) Lister

Mycetozoaed. 2. 53. 1911.

1875. Crateriachea mutabilis Rost., Mon. 126.

1894. Physarum cinereum (Batsch) Pers. ex List., Mycetozoa 55, in part.

1895. Physarum crateriachea List., Jour. Bot. 33 : 324.

Sporangia ovoid, cylindrical or subglobose, 0.4-0.6 mm. in diameter,
stalked or sessile, sometimes plasmodiocarpous, white, becoming
yellowish gray with the disappearance of the peridium, sessile or
stipitate, stipes when present yellow, with or without lime, often con-

72 THE MYXOMYCETES

nected by a hypothallus ; peridium thin, squamulose; capillitium per-
sistent, intricate, the nodules white, more or less confluent at the
center to form a real or a pseudocolumella; spores brownish purple,
spinulose, 7-10 ji. Plasmodium grayish, translucent.

The lime-knots may often form a pseudocolumella reaching nearly
to the top of the sporangium. Brandza reports plasmodiocarpous
forms from Rumania, developed as a result of unfavorable weather
conditions.

Forms with a capillitium nearly free from lime, the calcareous ma-
terial aggregated in the center to form a robust cylindrical columella,
such as distributed by Professor Brandza (No. 15), seem very close to
Diachea.

Reported from Europe, Africa, Ceylon, Japan.

44. Physartjm nicaraguense Macbr.

Bull. Nat. Hist. S. U. Iowa 2 : 382. 1893.

1894. Physarum compressum Alb. & Schw. ex Lister, Mycetozoa 53, in part.
1911. Physarum reniforme Lister, Mycetozoa ed. 2. 72, in part.

Sporangia multilobate or compound-contorted, below obconic, gray,
ribbed with calcareous thickenings; stem short, fuscous, longitudinally
wrinkled; hypothallus distinct, black; columella none, although the
lime massed at the center of each sporangium simulates one; capil-
litium white, densely calcareous, with heavy angular nodules connected
with comparatively short threads; spores violet, globose, spinulose,
about 12 ju in diameter.

This species somewhat resembles Physarum notabile, especially in
the amount of lime present in both capillitium and peridium, in the
fluted, sooty stipe, and the rough spores. Mr. Lister once regarded
it as the same. Nevertheless, it differs from that species in many defi-
nite particulars. In the first place, the sporangia are persistently
different in form and habit. They are obconic, nearly always com-
pound, convolute, or botryoid, in this respect somewhat resembling
P. polycephalum. Besides, the sporangia are uniformly much smaller,
and show constantly the strongly calcified center, much transcending
anything seen in P. notabile. The stipe also is peculiar, quite short,
an upward extension or sweep of the common hypothallus which is
usually very distinct or prominent; and, while the stipe is longitudinally
wrinkled, it is much less so than in the related species, and in a differ-
ent way. The spores are about the same in size, but differ in color,
in this respect agreeing rather with P. leucophceum.

In the Mycetozoa, 2nd edition, the present species is entered as a
synonym of two described by Massee: Tilmadoche reniformis Mass.,

PHYSARUM 73

Mon. 336, and Didymium echinosporum Mass., Mon. 239. But Massee's
description of his Tilmadoche is, naturally enough, at variance in
every important point with the facts in the species before us. Massee
describes the sporangia as deeply umbilicate below, sausage-shaped
and curved; the stem elongated, slender, erect, pale brown; capillitial
nodes scattered, fusiform, colorless or yellow; spores 16-17 fx. It is
evident that whatever Massee may have had in hand as he wrote, it
was not P. nicaraguense, which has spores 10-12 n and reverses the
remaining description.

But Didymium echinosporum also defines T. reniformis, since Lister
says they are based on two gatherings of one species. Of echinosporum
Massee says: "Bearing a superficial resemblance to Tilmadoche nutans,
but distinct in the capillitium, which contains no trace of lime, and
in the spores," the dimensions of the latter being given as 12-14 fx.
Again it is evident that whatever Massee had in hand when he wrote,
it was not P. nicaraguense in which the capillitium is almost Badhamia-
like, i. e., burdened with lime!

Worse than all, Mr. Massee's alleged types are in evidence; one
labelled P. reniforme includes forms of P. didermoides and of P. nica-
raguense; the other, labelled by Berkeley P. nutans, is P. nicaraguense
according to Petch, Mycet. Ceyl., who enters our species as from
Ceylon, and the names cited from Berkeley, Massee and others, as
synonyms. He remarks: "Probably Thwaites' 135 and 55 were mixed
during examination"! Doubtless! and some other things too! What
Massee did have beneath his lens, no one now may say but apparently
not in either case cited the physarum of Central America.

Nicaragua; Ceylon, perhaps throughout the tropics.

45. Physarum discoddale Macbr.

N. A. Slime-Moulds ed. 2. 74. 1922.

Sporangia gregarious, scattered, discoidal, depressed or umbilicate
above, sometimes almost annulate, snow-white, small, 0.5-0.7 mm.
in diameter, stipitate; stipe about twice the sporangium, pale yellow,
strand-like, but erect, even; hypothallus none; columella none; cap-
illitium strongly calcareous, almost as in Badhamia, aggregate at the
center, forming a pseudocolumella at the base of the peridium;
peridial wall firm, covered with innate patches of lime, somewhat
yellow at the base; spores minutely spinulose, violaceous, 9-11 fx.

Miss Lister considers this a synonym of P. javanicum Racib. But
Raciborski's description is of a larger species with thinner stalk and
saucer-like sporangium, externally roughly resembling Trichamphora

74 THE MYXOMYCETES

pezizoidea Jungh. This description does not apply to the present
species. It appears in late winter in undisturbed grass tufts and the
sporangia are scattered over the lower leaves. It displays a remarkable
amount of lime. The nodules, however, are not large; they are rounded
and connected here and there by the ordinary tubules characteristic
of a physarum.
California.

46. Physarum javanicum Racib.

Hedwigia 37 : 53. 1898.
1909. Physarella javanica (Racib.) Torr., Fl. Myx. 174.

Sporangia clustered, stalked, discoidal, somewhat convex below,
deep, saucer-shaped above, erect or somewhat nodding, 1 mm. broad,
0.25 mm. deep, the wall thin, white, the surface thickly covered with
small irregular lime granules, the upper part disappearing after ma-
turity, leaving the plate-like lower portion attached to the stalk;
stalk slender, grayish white, attenuate above, irregularly furrowed,
arising from a small hypothallus; capillitium dense, rigid, composed
of colorless, thin, often spindle-shaped tubes, connecting the numerous
elongated or triangular white lime nodules; spores violet, globose,
nearly smooth, 10-12 /*.

Externally resembling Trichamphora pezizoidea but differing in the
method of dehiscence, the structure of the capillitium and the color
of the stipe. Originally referred to the section Tilmadoche, but neither
the description nor Miss Lister's illustration suggest this. The spore
size is given as 9-10 fx in the Lister monograph. For the present we are
disposed to consider P. discoidale distinct, as noted under that species.
Hohnel (1909) thought P. javanicum much nearer to Trichamphora
than to any physarum.

Florida, Colombia; Java, South and East Africa.

47. Physarum compressum Alb. & Schw.

Consp. Fung. 97. 1805.
PI. V, Figs. 93, 94, 95.

1875. Physarum nephroideum Rost., Mori. 93, in part.

1875. Physarum lividum Rost., var. conglobatum Rost., Mon. 96, in part.

1875. Physarum candidum Rost., Mon. 96.

1876. Physarum affine Rost., Mon. App. 5.

1877. Didymium glaucum Phill., Grev. 5 : 114.
1882. Physarum phillipsii Balf. fil., Grev. 10 : 116.
1892. Physarum glaucum (Phill.) Massee, Mon. 284.

Sporangia more or less scattered, compressed-globose, or compressed-
reniform, often umbilicate, stipitate, sessile, or elongate and plasmodi-

PHYSARUM 75

ocarpous, calcareous, white or ashen; peridium thin, covered with
squamules, opening irregularly, usually by apical cleft; stipe, when
present, short, stout, more or less sulcate, dark brown or ashen;
capillitium a rather loose net, the nodules white, variable in size and
shape; spores purplish brown, warted, the warts sometimes irregularly
grouped, about 10-12.5 jx. Plasmodium grayish white.

Rather rare in North America. Known from Pennsylvania, Iowa,
Colorado, California, Oregon, Washington, also Puerto Rico, Bolivia,
Argentina. Cosmopolitan.

48. Physarum straminipes List.

Jour. Bot. 36 : 163. 1898.

Sporangia grayish white, obovoid or wedge-shaped, 0.7 mm. in
diameter, clustered or scattered, stipitate or sessile, when stipitate
stalks long, weak; peridium membranous, pale purple; capillitium a
persistent rigid net, the nodules white, rounded, sometimes aggregate
as a pseudocolumella; spores purple-brown, 10-11 fx, warted, the
papillae in definite patches. Plasmodium white.

Related to P. compressum.

Oregon, Chile; Europe, New Zealand.

49. Physarum newtoni Macbr.

Bull Nat. Hist. S. U. Iowa 2 : 390. 1893.

Sporangia simple, gregarious, short-stipitate or sessile, globose or
flattened, and then depressed and deeply umbilicate above, purple,
smooth, thin-walled; stipe when present very short and concolorous;
columella none; hypothallus none; capillitium abundant, delicate, with
more or less well developed nodules, which are also concolorous; spores
by transmitted light dark brown, thick-walled, rough, nucleated,
about 10 /x. Plasmodium dark violet.

A very handsome little species collected by Professor G. W. Newton
in Colorado, at an altitude of several thousand feet. Easily recognized
by its almost sessile, rose-purple, generally umbilicate sporangia.

Colorado; Japan.

50. Physarum roseum Berk. & Br.

Jour. Linn. Soc. 14 : 84. 1873.

Sporangia gregarious, globose, 0.4 mm. in diameter, rose-red, stip-
itate; sporangium wall membranous with innate clusters of purple-
red lime granules; stalk erect, slender, brown, rugulose, translucent;

76 THE MYXOMYCETES

columella none; capillitium lax, delicate, lilac, the nodules few, large,
purple-red, branching; spores reddish lilac or brown, minutely spin-
ulose, 7-10 n. Plasmodium rose-red.
Reported from Africa, Ceylon, Java, Borneo, Japan.

51. Physarum psittacinum Ditm.

in Sturm, Deutsch. Fl. Pilze 3 : 125. 1817.
PI. V, Figs. 96, 97.

1889. Physarum carlylei Massee, Grev. 17 : 56.

Sporangia scattered or gregarious, globose, depressed-globose, or
reniform; iridescent-blue or bronze, mottled with various tints, red,
orange, yellow, white; stipitate, stipe equal, or tapering slightly up-
ward, rugose, orange or orange-red, without lime, rising from a small
concolorous hypothallus; columella none; capillitium dense, crowded
with calcareous, brilliant orange nodules which are angular in outline
and tend to aggregate at the center of the sporangium; spore-mass
brown; spores by transmitted light pale brown, slightly but plainly
warted, 8-10 fx. Plasmodium orange-red.

Differs from P. pulcherripes Pk. in external coloration, the peridium
being blue or bronze, mottled, but not with lime; in the capillitium,
dense, calcareous, with large angular or branching nodes; in the stipe,
without lime; in the spores, a little larger than in P. pulcherripes,
and by transmitted light much more distinctly brown in color. The
sporangia are also broader in the present species, reaching 1 mm.

The variety fulvum Lister, reported from Iowa, Ceylon, Malay
Peninsula and Japan, has the lower part of the sporangium and the
stipe fulvous yellow instead of red or orange.

Rare. Maine, New Hampshire, New York, Massachusetts, Penn-
sylvania, West Virginia. Reported common in Europe, Japan.

52. Physarum leucopus Link

Mag. Ges. Nat. Fr. Berl. 3 : 27. 1809.
PI. V, Fig. 100.

1809. Physarum bullatum Lk., Mag. Ges. Nat. Fr. Berl. 3 : 27. 1809.
1829. Didymium leucopus (Lk.) Fr., Syst. Myc. 3 : 121.

Sporangia gregarious, stipitate, globose, 0.5 mm. in diameter, snow-
white, with a didymium-like covering of calcareous particles; stipe
white, not long, conical or tapering rapidly upward, slightly sulcate,
brittle, from an evanescent hypothallus; columella none or small;
capillitium, consisting of rather long hyaline threads, connecting the
usual calcareous nodes, which are large, angular, snow-white; spore-

PHYSARUM 77

mass black; spores by transmitted light violet-brown, distinctly warted,
about 10 ix. Plasmodium white, often with blue, green or yellow tints.

The snow-white, nearly smooth stem and the small sporangium
covered with loose calcareous granules distinguish this rare species.
It develops on leaves and looks like a small Didymium squamulosum.

Rare. Maine, Ohio, Michigan, Wisconsin, Iowa, Oregon, Colombia;
Europe, South Africa, Java.

53. Physarum leucopjleum Fr.

Symb. Gast. 24. 1818.
PL V, Figs. 98, 99.

1797. Trichia filamentosa Trentep., in Roth, Cat. Bot. 1 : 227.

1817. Physarum conglobatum Ditm., in Sturm, Deutsch. Fl. Pilze 3 : 81.

1836. Diderma terrestre Fr. ex Weinm., Hymeno-Gastero-Myc. 574.

1882. Physarum granulatum Balf. fil., Grev. 10 : 115.

1884. Physarum imitans Racib., Rozpr. Mat.-Przyr. Akad. Krak. 12 : 73.

1892. Physarum readeri Massee, Mon. 282.

1893. Tilmadoche nephroidea Cel. fil., Myx. Bohm. 69.

1894. Physarum nutans Pers. var. leucophaum (Fr.) Lister, Mycetozoa 51.

Sporangia scattered or gregarious, stipitate; peridium globose or
subdepressed, occasionally short-cylindric, 0.5-1 mm. in diameter;
plano-convex, but never umbilicate below, erect, bluish ashen; stipe
short, rugose, subsulcate, fuscous, brown, or sometimes almost white,
even or slightly attenuate upward from a thickened base or some-
times from an indistinct hypothallus; capillitium dense, intricate; the
nodules white, with comparatively little lime, thin, expanded, angular
or branching; columella none; spore-mass black, spores dark violaceous,
minutely roughened, about 9-11 fx.

This extremely delicate and beautiful form is certainly not to be
referred to Tilmadoche alba (Bull.). Fries, who seems to have known of
P. compressum A. & S., and refers it to P. nutans Pers., annotates
the present species: "Species especially remarkable in the stipe, in
the internal structure, and in its whole habit, nor is there any other
with which it may be compared. . . . Peridium thin, . . . not uni-
form, . . . presently breaking up into laciniate scales; at first yellow,
then bluish-ashen; when empty, white. The form inconstant, globose,
depressed, but never umbilicate at the base." If we may judge by
what Fries says on the subject, he certainly distinguished clearly be-
tween this species and T. alba (Bull.), to say nothing of the stouter,
larger, in every way coarser forms called by Rostafinski P. nefroideum,
P. compressum and P. lividum.

This shadowy little species has had an eventful history, dipping in

78 THE MYXOMYCETES

and out of our story in most uncertain fashion. Beginning with Fries,
as noted, it received confirmation at the hands of de Bary, and by
Rostafinski was given priority over a long list of synonyms, and figured.
The earlier English authors follow Rostafinski, but for Lister in the
Mycetozoa, 51, the species becomes a synonym of T. alba as P. nutans,
the description appropriately enlarged to receive it. Meantime
American students generally confused it with the tilmadoches on the
one hand and P. nefroideum Rost. (supposed) on the other. In 1897,
Robert Fries in Sver. Myxom. Flora, brings the species again to view
as copartner with P. nutans. In the Mycetozoa, 1st and 3rd editions,
it appears as a variety of the same, in the 2nd edition as a subspecies.

The resemblance of P. album or P. nutans is chiefly, as intimated, a
matter of definition ; real differences are found in the irregular capilli-
tium, fitting a globose sporangium, in the character of the stipe and the
consequent pose. See under P. nutans and P. notabile.

If the species is to be maintained as distinct, as we believe it should
be, and if Trichia filamentosa Trentep. is correctly regarded as syn-
onymous, that specific name should have preference.

Widely distributed, especially in temperate regions.

54. Physarum maculatum Macbr.

Bull. Nat. Hist. S. U. Iowa 2 : 383. 1893.
1911. Physarum tenerum Rex ex Lister, Mycetozoa ed. 2. 52, in part.

Sporangia scattered or gregarious, very small, 0.3-0.4 mm., dull
gray, thin-walled, dotted with minute, white calcareous granules,
stipitate; stipe long, about 2 mm., stout, attenuated upward, striate
longitudinally or wrinkled, filled with irregular yellow masses of lime
and accordingly bright yellow in color; columella none; capillitium
forming a dense net, with comparatively small yellow nodular thicken-
ings; spores globose, purplish, each minutely papillose and displaying
several scattered spots occasioned by local development of the papilla? ;
diameter of the spores 9-10 /*.

This species was set up for the reception of certain material collected
by Professor Shimek, in 1892, in Nicaragua. It remains so far unique.
The small globose sporangium mounted upon a long upwardly taper-
ing stipe, 0.5 mm. thick below, but narrowed at the extreme base where
it is lightly attached, a stem which is simply a sack stuffed with yellow
lime granules; — this and the yellow capillitium are distinguishing
features. The capillitium and spores suggest Physarum viride, but
the entire habit precludes such reference. Perhaps nearest to P. mel-
leum.

Miss Lister thinks this the same as P. tenerum Rex. But the whole

PHYSARUM 79

habit and external appearance are different; the stipe notably long,
clumsy, surcharged with lime; a very singular form.
Castillo, Nicaragua.

55. Physarum notabile Macbr.

N. A. Slime-Moulds ed. 2. 80. 1922.
PI. VI, Figs. 103, 104.

1874. Didymium connatum Pk., Rept. N. Y. State Mus. 26 : 74.
1879. Physarum polymorphum (Mont.) Rost. ex Peck, Rept. N. Y. State Mus.
31 : 55, non Rost.

1893. Physarum kucophceum Fr. ex Macbr., Bull. Lab. Nat. Hist. Iowa 2 : 156,
non Fr.

1894. Physarum compressum Alb. & Schw. ex Lister, Mycetozoa 53, in part.
1896. Physarum connexum Lk. ex Morg., Jour. Cin. Soc. Nat. Hist. 19 : 20, in

part.
1896. Physarum confluens Pers. ex Morg., Jour. Cin. Soc. Nat. Hist. 19 : 22.
1899. Physarum nefroideum Rost. ex Macbride, N. A. Slime-Moulds 41, in

part.
1911. Physarum connatum (Pk.) Lister, Mycetozoa ed. 2. 71, non Ditm., non

Schum.

Sporangia gregarious, sessile, stipitate, or even plasmodiocarpous;
when stipitate, depressed, varying at times to irregular reniform in
the same colony, or globose; peridium strongly calcareous, cinereous-
white; stipe variable, generally tapering upward, always distinctly
deeply plicate-furrowed throughout, in color dark, opaque, sometimes
touched with white or gray, or white from a coating of calcareous
granules; capillitium abundant, the white lime-knots, varying in size
and shape, connected by rather long hyaline threads, with here and
there an empty node; spore-mass black, by transmitted light dark,
sooty brown, minutely papillose, 10-11.5 /jl.

This remarkable species, while not at all difficult of recognition to
one familiar with its phases, is withal very difficult to define. Nor-
mally stipitate, it often shows from the same plasmodium all sorts of
forms, the shape of the fructification dependent apparently upon ex-
ternal conditions prevalent at the time. The amount of calcium also
varies, especially in the capillitium, where there is usually much, with
a tendency to the formation of something like a pseudocolumella;
the outer net in such cases nearly destitute. The calcium in the stipe
also varies; the black or brown stipes are, of course, free from it; the
gray or white, calcareous.

Eastern United States and Canada, Brazil; Europe.

Physarum compressum Skvortz. non Alb. & Schw., Phil. Jour. Sc.
46 : 86, 1931, agrees, so far as the description goes, with some forms

80 THE MYXOMYCETES

of P. notabile except that the lime-knots are said to be dark yellow-
brown.

56. Physarum pusillum {Berk. b° Curt.) Lister

Mycetozoa ed. 2. 64. 1911.
PI. VI, Figs. 105, 106.

1873. Didymium pusillum Berk. & Curt., Grev. 2 : 53.

1881. Physarum nodulosum Cke. & Balf., Rav. N. A. F. Exsic. 479. Not

published.
1889. Badhamia nodulosa (Cke. & Balf.) Massee, Jour. Myc. 5 : 186.
1891. Physarum calidris Lister, Jour. Bot. 29 : 258.
1896. Craterium nodulosum (Cke. & Balf.) Morg., Jour. Cin. Soc. Nat. Hist.

19 : 15.
1899. Physarum nodulosum Cke. & Balf. ex Macbride, N. A. Slime-Moulds 51.

Sporangia gregarious, small, stipitate, globose, 0.4-0.6 mm. in di-
ameter, grayish white at first, becoming white as the spores are freed,
with a brown base, the sporangium walls thin, rugose, more or less
encrusted with lime, breaking up irregularly; stipe slender, longer
than the sporangium, attenuate upward or even, bright brown, rugose,
merging into the shallow, cup-like base of the sporangium; columella
none; capillitium with lime-knots more or less abundant, white, often
uniting, somewhat badhamioid; spore-mass black; spores by trans-
mitted light pale lilac-brown, minutely warted, 10-12 fx.

One of the smaller species of the genus, by its proportionally long
stipe and small round sporangium reminding one somewhat of P. glo-
buliferum; much smaller, however, and in every way different. The
generic characters are mixed, and the species has been accordingly
variously referred. The lower part of the peridium is sometimes per-
sistent after the dehiscence, and in that respect suggests Craterium.
But this character is not constant, and even at best the persisting
part is very small, not greater than in P. melleum, for example. On
the other hand, the capillitium in some sporangia is strongly calcareous,
suggesting Badhamia, but in most sporangia the physarum characters
are sufficiently clear.

The name Physarum nodulosum seems not to have been effectively
published until 1899, although the specific name nodulosa was used
by Massee (1889) and Morgan (1896). Didymium pusillum Berk. &
Curt, was published in 1873. The type at Kew contains two species,
this and a didymium. But Sturgis reported that the specimen in
Curtis' herbarium, presumably a co-type, shows only the physarum.
On the face of the record, Physarum pusillum (B. & C.) Lister is the
valid name.

Canada to Pennsylvania and Iowa; cosmopolitan.

PHYSARUM 81

57. Physarum tropicale Macbr.

N. A. Slime-Moulds 45. 1899.
1925. Physarum connatum (Pk.) Lister, Mycetozoa 3 ed. 51, in part.

Sporangia scattered, gregarious, turbinate, short-stipitate, blue-gray,
about 1 mm. in diameter; peridium above iridescent, green, blue, etc.,
dotted with minute flecks of white, below limeless, purple or bronze,
shading to the brown of the stipe; stipe short, stout, slightly rugose,
cylindric, non-calcareous, brown; columella none; hypothallus none;
capillitium abundant, the nodes generally calcareous, small, uniform,
angular, white, uniformly distributed; spore-mass black; spores dark
violet-brown, distinctly and closely warted, 12-15 fj,.

A large handsome species recognizable by the peculiar turbinate
sporangium, with its iridescent peridial wall in which green strongly
predominates above, bronze below. The distinction between the
upper and lower peridium would suggest Craterium, but the internal
structure is not at all Craterium-like. The capillitium is typical of
Physarum. The color suggests those forms of P. leucopkceum Fr.
described by Rostafinski as var. violascens. From this species it is at
once distinguished by its much larger sporangia and larger and rougher
spores.

Mexico.

58. Physarum simplex M. E. Peck

Am. Jour. Bot. 19 : 136. 1932.

Sporangia stipitate, globose or a little depressed, minute, 0.2 to
0.3 mm. in diameter, very dark or sometimes dull yellowish; stipe
0.5 to 2 mm. long, slender, narrowed upward, irregularly grooved,
often very crooked and drooping above, light yellowish, little or not
at all calcareous; hypothallus none; peridium thin, often strewn with
abundant flakes of lime but sometimes nearly limeless, then appear-
ing black, persistent below; columella none; capillitium of very delicate
threads springing from the peridial floor, with a few small yellowish
gray calcareous nodes or none, and almost without dilations at the
intersections; spores violaceous brown, minutely roughened, 7-9 n in
diameter.

A very delicate, minute species found twice in the vicinity of Salem,
Oregon. It is related to P. flavicomum Berk., differing in the longer
stipe, the more calcareous peridium and the less dense capillitium
with very few calcareous nodes.

Oregon. Dead bark of Pseudotsuga.

82 THE MYXOMYCETES

59. Physarum albescens Ellis

in Macbride, N. A. Slime-Moulds ed. 2. 86. 1922.
PL VI, Figs. 107, 108.

1893. Physarum auriscalpium Cke. ex Macbride, Bull. Lab. Nat. Hist. Iowa
2 : 158, in part.

1894. Physarum virescens Ditm. var. nitens List., Mycetozoa 59, in part.
1899. Leocarpus julvus Macbr., N. A. Slime-Moulds 82.

1911. Physarum julvum (Macbr.) List., Mycetozoa ed. 2. 60, non Fries.

Sporangia gregarious or scattered, ovoid or globose, occasionally
subplasmodiocarpous, pale yellowish or fulvous, opening irregularly
above, stipitate or sessile; peridium double, the outer layer more or
less calcareous, the inner delicate, almost indistinguishable, persistent
below as a shallow cup; stipe usually long, weak, striate, fulvous or
yellow; hypothallus distinct, venulose or more or less continuous;
capillitium pallid or white, dense, flattened and expanded at the axes,
with here and there below large continuous yellow calcareous nodules;
columella none; spore-mass black; spores by transmitted light dark
brown, rough, 12-15 ju. The Plasmodium is yellow on fallen leaves and
twigs.

The capillitium is curious, largely flattened and membranous and
much like that of Leocarpus, while the general aspect is that of a did-
erma. Forms occur, however, in which the capillitium is more typically
physaroid; such forms may have but a single layer to the peridium.
Reference to the taxonomic history will be found in N. A. Slime-
Moulds, ed. 2, pp. 87-89, where the name used by Ellis, P. albescens,
was published.

Iowa, Louisiana, Colorado, Montana, Idaho; Switzerland.

60. Physarum citrinellum Peck

Rept. N. Y. Mus. Nat. Hist. 31 : 57. 1879.
PL VI, Figs. 109, 110.

1869. Diderma citrinum Pk., Rept. N. Y. State Mus. 22 : 89, non Fr.
1894. Craterium citrinellum (Pk.) List., Mycetozoa 74.

Sporangia gregarious or scattered, globose, 0.6-0.8 mm. in diameter,
short-stipitate, pale yellow or ochraceous, smooth or slightly rough-
ened by the presence of minute lime particles; peridium double, the
outer calcareous, fragile, the inner very delicate, with here and there
a calcareous thickening, ruptured irregularly; stipe very short, half
the sporangium, orange-brown, translucent, furrowed, expanded below
into an imperfectly defined hypothallus; capillitium abundant, the
nodes stellate-angular, large, the internodes delicate, short; spore-

PHYSARUM 83

mass black; spores violaceous brown by transmitted light, strongly
spinulose, 10-12.5 fx. Plasmodium greenish.

A very distinct and handsome species. Easily recognizable at sight
by its large, globose, almost sessile and yet distinctly stalked sporangia.
The color to the naked eye is pale ochraceous or buff. Only under a
moderate magnification do the citrine tints come out.

In the Twenty-second N. Y. Report Peck incorrectly referred
this species to Physarum citrinum Schum. On the appearance of
Rostafinski's Monograph, Peck changed the name to P. citrinellum.
Under the last name the species has been generally recognized in the
United States and distributed.

Eastern United States, Oregon; Germany, Rumania, Japan.

61. Physarum variabile Rex

Proc. Acad. Nat. Sc. Phila. 1893 : 371.

1925. Physarum sulphureum Alb. & Schw. ex Lister, Mycetozoa ed. 3. 26,
in part.

Sporangia scattered, stipitate, substipitate or sessile, about 1 mm.
high, regularly or irregularly globose, ellipsoidal, obovate or cylindric-
clavate in shape; sporangium wall sometimes apparently thick, of a
dingy yellow or brownish ochre color, slightly rugulose on the surface,
crustaceous, brittle, rupturing irregularly, sometimes thin, translucent,
covered externally with flat circular calcareous masses falling away in
patches; stipes nearly equal, occasionally much expanded at the base,
rough, longitudinally rugose, variable in size, sometimes one-third of
a millimeter high, sometimes a mere plasmodic thickening of the base
of the sporangium ; color of stipes varying from a yellowish white to a
dull brownish gray; capillitium a small-meshed network of delicate
colorless tubules with large, many-angled, rounded masses of white,
or rarely yellowish white lime granules at the nodes; no true colu-
mella, but often a central irregular mass of white lime granules; spores
dark violet-brown, verruculose, 9-10 fx.

In the English monograph this is included in P. sulphureum; Brandza
would recognize it as a variety, differing mainly in shape from typical
forms of that species; Rex thought the color difference significant.
What were previously regarded as sessile forms of Rex's species are
now commonly referred to P. sessile Brandza, but Mr. Hagelstein is
of the opinion that there are sessile forms of P. variabile. In view of
the uncertainty, the species may be maintained pending further
information.

Rare. Pennsylvania, New York, Venezuela; Rumania.

LIBRARY

84 THE MYXOMYCETES

62. Physarum carneum G. List. & Sturgis

Jour. Bot. 48 : 63. 1910.

Sporangia gregarious, stipitate, rarely sessile or forming short plas-
modiocarps, subglobose, 0.5 mm. in diameter, ochraceous yellow above,
flesh colored below; peridium membranous, pale yellow, lime granules
evenly distributed; stipe short, translucent, pinkish flesh colored;
capillitium dense, nodules white; spores purplish brown, spinulose,
8-9 ul.

Differs from P. citrinellum in the membranous peridium, flesh colored
stalks and smaller spores.

Colorado, Montana, Washington, Oregon; Europe.

63. Physarum flavicomum Berk.

Hooker Jour. Bot. 4 : 66. 1845.
PI. VI, Figs. Ill, 112, 113.

1873. Physarum cupripes Berk. & Rav., Grev. 2 : 65.
1875. Physarum berkeleyi Rost., Mon. 105, in part.
1892. Didymium flavicomum (Berk.) Massee, Mon. 242.

Sporangia gregarious, spherical or lenticular, small, 0.3-0.5 mm. in
diameter, at first fuliginous throughout, stipitate; peridium thin,
destitute of lime, iridescent, breaking up and deciduous in patches,
except at the base; stipe twice the diameter of the peridium or more,
golden or brown, fluted, often twisted, not hollow, tapering upward
from a small but distinct, radiant hypothallus; columella none; cap-
illitium dense, persistent, the nodes frequently calcareous, elongate
and vertical, especially below, yellow; spore-mass brown; spores by
transmitted light bright violaceous brown, faintly papillose, 9-10 /jl.

This species is instantly distinguishable from all cognate forms by
its peculiar sooty color. Not less is the species structurally marked
by its capillitium. The latter below is exactly as in the species formerly
referred to Tilmadoche. Indeed, the present species unites characters
supposed to distinguish Physarum from Tilmadoche, and thus justifies
those who bring all the species of both genera together under one
generic name. In any case the species is by its capillitium entirely
distinct from P. galbeum, as well as by the structure of the stipe and
the peridial surface. The Plasmodium, at first watery, emerges from
decayed elm logs and soon takes on a peculiar greenish tint preserved
somewhat in the mature fruit.

Rostafinski (Monograph 105, 106), rejects Berkeley's specific name,
flavicomum, because it refers to the somewhat indefinite color. As

PHYSARUM 85

this is no valid reason for change, we retain Berkeley's specific name,
which by general consent has priority.

Not common. New Jersey, South Carolina, Ohio, Minnesota, Iowa;
reported from South Africa, Java, Japan, Australia, New Zealand.

64. Physarum sulphureum Alb. & Schw.

Consp. Fung. 93. 1805.
PL VI, Figs. 114, 115.

1818. Physarum flavum Fr., Symb. Gast. 22.

1877. Physarum sulphureum Alb. & Schw. ex Cooke, Ann. Lye. Nat. Hist.
N. Y. 11 :384.

Sporangia gregarious, subglobose, rugulose-squamulose, 0.6-0.8 mm.,
sulphur-yellow, stipitate; peridium membranous, covered with cal-
careous scales; stipe stout, white, charged with lime, furrowed; col-
umella none; capillitium strongly calcareous, the nodules large, white;
spores violaceous, rough, 9-1 1 fx. Plasmodium yellow.

The description and figure given by Schweinitz, 1805, leave no
doubt as to what he had in hand. Twenty or thirty years later,
having spent the interval in this country — bishop, indeed, of the
Moravian churches, but a student of fungi all the while — he reports
the same thing from this country. Cooke also lists it in Myxomycetes
of the United States.

Eastern United States to Wisconsin and Iowa, rare, South America;
Europe, Japan.

65. Physarum auriscalpium Cooke

Ann. Lye. Nat. Hist. N. Y. 11 : 384. 1877.
PL VI, Figs. 116, 117.

1898. Physarum auriscalpium Cooke ex Lister, Jour. Bot. 36 : 115.

1899. Physarum auriscalpium Cooke ex Macbride, N. A. Slime-Moulds 38.
1911. Physarum auriscalpium Cooke ex Lister, Mycetozoa ed. 2. 60, in part.

Cooke's original description is as follows:

"Sporangia globose, depressed, ochrey yellow, covered with orange
mealy scales above, with a very short, almost obsolete, stem. Colu-
mella not evident. Capillitium strongly developed, expanded at the
angles, which are filled with yellow granules of lime, combined into a
network; deposits of lime in irregular, angular masses. Spores violet-
brown, nearly smooth or minutely warted, .013-015 mm. diam."

Reference is made to fig. 253 of the same author's Myxomycetes of
Great Britain, which merely indicates the depressed globose peridium
with a tendency for the lower portion to remain as a cup, and the
short, thick stipe. The species is not mentioned in the text. The spores

86 THE MYXOMYCETES

rarely exceed 12 /x in our material, and mostly range from 9-11 /x.
Cooke's specimens, originally collected by Ravenel in (South?) Carolina
are still preserved in London.

Rare in the United States: Reported from Massachusetts, New
York, "Carolina," Wisconsin, Iowa, Colorado, Montana, Oregon,
California; Europe. Reported from South America, South Africa,
southern Asia and Japan, but most reports are probably more than
questionable.

66. Physarum tenerum Rex

Proc. Acad. Nat. Sc. Phila. 1890 : 192.
PI. VI, Figs. 118, 119.

1899. Physarum obrusseum (Berk. & Curt.) Rost. ex Macbride, N. A. Slime-
Moulds 52, n on Rost.

Sporangia stipitate, spherical, erect or nodding, 0.3-0.4 mm. in
diameter; peridium single, membranous, but thickly studded with
circular, flattened, yellow granules of lime, dehiscing by petal-like
lobes; stipe 1-1.5 mm. long, subulate, slender, opaque, striate and dark
below, pale yellow above; columella none; capillitium delicate, of
yellow, rounded nodes, connected by hyaline threads, many of the
intersections limeless; spores dark brown, delicately warted, 7-8 fx.
Plasmodium yellow.

This delicate Physarum, very fragile and evanescent, seems to be
distinct, by reason of its characteristic rounded nodules, from any
similar stipitate species. It resembles P. citrinum, but is more slender,
the color is grayish yellow, and it lacks a columella. It varies a little
according to locality. Ohio specimens are a little larger and have
thicker and more calcareous stipes than is usual in those from Phila-
delphia. The walls of the sporangia when fully matured generally
break into several petal-like segments which finally become reflexed.

Rare. New Jersey, Pennsylvania, Virginia, Ohio, Louisiana, Iowa,
Texas, Montana, Washington, West Indies, South America; Portugal,
Rumania, Ceylon, Malay Peninsula, Java, Japan.

67. Physarum galbeum Wingate

in Macbride, N. A. Slime-Moulds 53. 1899.
PI. IV, Fig. 64.

1890. Physarum galbeum Wing., Ellis N. A. F. 2491, without description.
1892. Physarum petersii Berk. & Curt, ex Massee, Mon. 295, in part.
1894. Physarum berkeleyi Rost. ex List., Mycetozoa 47, in part.

Sporangia scattered, globose, 0.4-0.5 mm. in diameter, stipitate,
often nodding, golden yellow, peridium exceedingly thin, breaking up

PHYSARUM 87

into patches on which the yellow lime granules are conspicuous; stipe
non-calcareous, pale brown or amber colored, longitudinally wrinkled,
about one and one-half times the diameter of the peridium; columella
none; hypothallus none; capillitium dense, of extremely delicate yel-
low threads, the nodes only here and there calcareous, the lime-knots,
when present, small, angular, yellow; spore-mass pale brown; spores
almost smooth, lilac- or violet-tinted, 7.5-10 fx.

Distinguished among the small delicate species with which it will
be naturally associated, by the yellow, richly calcareous wall of the
globose sporangium and the almost limeless capillitium. The stipe is
hollow and contains irregular masses of refuse granular matter, but
no lime so far as we have been able to discover. P. flavicomum, to
which the species is related most closely, differs in having the wall
non-calcareous, iridescent, as well as in the color throughout; in the
character of the capillitium, in which lime is abundant; and in the
absence of refuse matter in the stem.

Nova Scotia, Vermont, Pennsylvania, Iowa, Minnesota; Europe,
Ceylon.

68. Physarum oblatum Macbr.

Bull. Nat. Hist. S. U. Iowa 2 : 384. 1893.
PL VI, Figs. 120, 121.

1896. Craterium maydis Morg., Jour. Cin. Soc. Nat. Hist. 19 : 15.
1909. Physarum maydis (Morg.) Torr., Fl. Myx. 193.

Sporangia gregarious, stipitate, small, bright yellow, globose or
depressed-globose, rough; stipe reddish brown or fuliginous, even,
short, slender; hypothallus scant, black, or none; columella none;
threads of the capillitium hyaline or yellowish, delicate, connecting
the rather dense and abundant irregular yellow nodes; spore-mass
brownish black, spores violaceous, minutely but distinctly spinulose,
9-11/*.

This species is easily recognizable by its brilliant yellow color,
somewhat rugose, sometimes scaly peridium, its richly calcareous
capillitium, also bright yellow where not weathered or faded, and its
dark brown, translucent, non-calcareous stem. After dehiscence, the
base of the peridium often persists as a cup. This circumstance, with
the fact that decaying maize-stalks and leaves are a favorite habitat,
led Professor Morgan to its description as Craterium maydis. But it is
doubtless a physarum, occurring on habitats of all sorts.

Ohio to Iowa, Colorado and Washington, West Indies; Germany,
Rumania, Uganda, Java.

88 THE MYXOMYCETES

69. Physarum gyrosum Rost.

Mon. 111. 1875, in part.
PL VI, Figs. 123, 124.

1892. Physarum cerebrinum Massee, Mon. 306.

1902. Fuligo gyrosa (Rost.) Jahn, Ber. Deutsch. Bot. Ges. 20 : 272.

Sporangia yellowish gray or pinkish gray, gyrose, irregular, often form-
ing dense, venulose, laterally compressed plasmodiocarps, sometimes
subaethalioid, usually sessile upon a common strongly developed hypo-
thallus; sometimes isolated and irregularly globose, or with a slender,
dull red stalk formed by a strand of the hypothallus; capillitium deli-
cate, the nodules elongate, variable in size; spores pale violaceous
brown, minutely spinulose, 7-10 /*. Plasmodium yellowish white.

The present conception of this species is that of Jahn rather than
that of Rostafinski, although Jahn placed it in the genus Fuligo, to
which, indeed, it bears much resemblance. Rostafinski seems to have
included under this name not only the present species, but also
Fuligo muscorum and certain plasmodiocarpous phases of Physarella
oblonga.

The species suggests a large, sessile form of Physarum polycephalum
but is distinct.

Widespread, reported from every continent, but not very common
as a rule. In North America recorded from New York, Pennsylvania,
District of Columbia, Virginia, Mississippi, Iowa.

70. Physarum polycephalum Schw.

Schr. Naturforsch. Ges. Leipzig 1 : 63. 1822.
PL VI, Fig. 122.

1829. Didymium polycephalum (Schw.) Fr., Syst. Myc. 3 : 122.

1837. Didymium polymorphum Mont., Ann. Sc. Nat. 2 ser. 8 : 361.

1837. Didymium gyrocephalum Mont., Ann. Sc. Nat. 2 ser. 8 : 362.

1869. Didymium obrusseum Berk. & Curt., Jour. Linn. Soc. 10 : 348.

1869. Didymium tenerrimum Berk. & Curt., Jour. Linn. Soc. 10 : 348.

1875. Physarum polymorphum (Mont.) Rost., Mon. 107.

1875. Tilmadoche gyrocephala (Mont.) Rost., Mon. 131.

1876. Physarum obrusseum (Berk. & Curt.) Rost., Mon. App. 11.
1884. Physarum multiplex Pk., Bull. Torrey Bot. Club 11 : 50.

1899. Tilmadoche polycephala (Schw.) Macbr. N. A. Slime-Moulds 57.

Sporangia spherical or irregular, gyrose-confluent, helvelloid, um-
bilicate below; peridium thin, ashy, covered with evanescent yellow
squamules, fragile; stipe from an expanded membranaceous base,
long-subulate, yellow; spores minutely spinulose, violet, 9-11 /x. Plas-
modium yellow.

A most singular and well-defined species, occurring in masses of

PHYSARUM 89

decaying leaves or on rotten logs. The Plasmodium, at first colorless, as
it emerges for fructification becomes white, then yellow, spreading far
over all adjacent objects, not sparing the leaves and flowers of living
plants; at evening, slime, spreading, streaming, changing; by morning,
fruit, a thousand stalked sporangia with their strangely convoluted
sculpture. The evening winds again bear off the sooty spores, and
naught remains but twisted yellow stems crowned with a pencil of
tufted silken hairs.

Although Rostafinski's description of this species is accurate and
marks exactly a tilmadoche and is very different from his description
of Physarum polymorphum, nevertheless it is probable that both de-
scriptions have reference to the same thing. All specimens on which
both species were based were American; P. polymorphum, North
American. But the only North American form to which reference can
be made is that called by Schweinitz P. polycephalum and, fortunately,
sufficiently described. Furthermore, Rostafinski, under T. gyrocephala,
himself affirms the probable identity of Montagne's Didymium gyro-
cephalum with the Schweinitzian species, and uses Montagne's specific
name provisionally. For these reasons it seems proper to write the
species as above.

This species is so common that its plasmodium and fructification may
be easily observed. Professor Morton E. Peck says of P. polycephalum:
"In one instance I observed a plasmodium for twelve successive days
on the surface of a decaying stump. During this period it crept all
around the stump and from top to bottom several times. At one time
the color was bright yellow; at another, greenish yellow; and once,
shortly before fruiting, it became clear bright green. A heavy rain fell
upon the plasmodium but it appeared to sustain little injury and
ultimately developed normal sporangia." The plasmodium feeds
largely on the hymenium of various fleshy and subfleshy fungi, and
may readily be cultured on such substrata. See Howard (1931).

The var. obrusseum (Berk. & Curt.) List, is merely a phase with the
sporangia more or less free instead of united. It seems to merge im-
perceptibly into the other forms.

Widely distributed and common, from Maine and Canada to Wash-
ington and south to Nicaragua, Puerto Rico, British Guiana; France,
Rumania, Malay Peninsula, Japan.

71. Physarum dictyospermum List.

Jour. Bot. 43 : 112. 1905.

Sporangia subglobose, short-stalked, erect, scattered, 0.5-0.6 mm.
in diameter, dull orange, dark chestnut or olive-brown, glossy, spo-

90 THE MYXOMYCETES

rangium wall membranous, rather firm, orange; stalk 0.1-0.7 mm. high,
slender, black, enclosing refuse matter, sometimes yellow above from
superficial lime granules; columella black, conical or clavate, short to
two- thirds the height of the sporangium; capillitium abundant, per-
sistent, of colorless threads with small, fusiform, orange-red nodes;
spores pale purplish gray, reticulated, five to six meshes on one side,
meshes fainter and less regular on the other, sometimes marked merely
by short curved lines, 10-11 fx.

The above description is slightly abridged from Lister, 3rd edition,
35. It is suggested that its relationships are with P. psittacinum be-
cause of the orange nodes and peridial deposits. The capillitium, how-
ever, is decidedly tilmadochoid as described.

Chile; Switzerland, New Zealand, Australia.

72. Physarum nutans Pers.

Ust. Ann. Bot. 15 : 6. 1795.
PI. VI, Figs. 125, 126.

1791. Sphcsrocarpus albus Bull., Champ. 137.

1791. Stemonitis alba (Bull.) GmeL, Syst. Nat. 2 : 1469.

1797. Trichia nutans (Pers.) Trentep., in Roth, Cat. Bot. 1 : 227.

1803. Trichia cernua Schum., Enum. PL Saell. 2 : 241.

1829. Physarum cemuum (Schum.) Fr., Syst. Myc. 3 : 130, in part.

1829. Didymium marginatum Fr., Syst. Myc. 3 : 115.

1829. Didymium furfur aceum Fr., Syst. Myc. 3 : 116.

1829. Physarum gracilentum Fr., Syst. Myc. 3 : 133.

1849. Tilmadoche cernua (Schum.) Fr., Summ. Veg. Scand. 454.

1873. Tilmadoche nutans (Pers.) Rost., Versuch 10.

1875. Tilmadoche gracilenta (Fr.) Rost., Mon. 129.

1899. Tilmadoche alba (Bull.) Macbr., N. A. Slime-Moulds 58.

Sporangia gregarious, depressed-spherical, 0.4-0.7 mm. in diameter,
sometimes smaller, stipitate, umbilicate, gray or white, thin-walled, erect
or nodding; stipe long, tapering upward, brown or black below, ashen
white above, lightly striate, graceful; capillitium abundant, threads del-
icate, intricately combined in a loose persistent network with occasional
minute, rounded, or elongate white calcareous nodules; spores minutely
roughened, globose, about 10 n.

The nodding, lenticular, umbilicate sporangium, barely attached to
the apiculate stipe, is sufficient to distinguish this elegant little species,
recognized and quite aptly characterized by mycologists for more than
one hundred years. The stipe is usually white above, fuscous below,
at the apex almost evanescent; hence the cernuous sporangia. The
same character is less strikingly manifest in the species next following.

The Plasmodium is bright yellow, sometimes greenish. Brought in

PHYSARUM 91

from the field and maturing under a bell-jar, the color changes to a
watery white just before the sporangia rise in fruit.

As Sphcerocarpus albus, Bulliard first prescribed the limits by which
the species is at present bounded. The description by Fries (Syst.
Myc. 3 : 128) is especially graphic: "Peridium very thin, in form quite
constantly lenticular, umbilicate at base, at first smooth, then uneven,
generally laciniate-dehiscent, the segments persistent at least at base."
Physarum album Fr. (Syst. Myc. 3 : 147) is regarded as a synonym of
Didymium difforme and should not be revived for a different species,
hence Persoon's name, generally accepted, should stand. P. album
Fuckel (Rhen. Fl. No. 1469, 1865), is believed to be P. cinereum.

Var. robustum Lister is applied to an erect, sometimes plasmodiocar-
pous form, often exhibiting a pseudocolumella.

Common and world-wide in distribution.

73. Physarum viride (Bull.) Pers.

Usteri Ann. Bot. 15 : 6. 1795.
PI. VI, Figs. 127, 128.

1791. Sphcerocarpus viridis Bull., Champ. 135.

1791. Sphcerocarpus luteus Bull., Champ. 136.

1791. Stemonitis viridis (Bull.) Gmel., Syst. Nat. 2 : 1469.

1794. Physarum aureum Pers. in Roemer, Neu. Mag. Bot. 1 : 88.

1829. Physarum nutans var. viride Fr., Syst. Myc. 3 : 129.

1829. Physarum nutans var. aureum Fr., Syst. Myc. 3 : 129.

1875. Tilmadoche mutabilis Rost., Mon. 129.

1880. Tilmadoche viridis (Bull.) Sacc, Michelia 2 : 263.

Sporangia globose, flattened or lenticular, 0.3-0.5 mm., plane or
concave below, variously colored — yellow, greenish yellow, rusty
orange — stipitate, nodding; the peridium splitting irregularly or
reticulately; stipe subulate, variable in length and color, through
various shades of yellow and red to black; capillitium strongly de-
veloped, concolorous with sporangium, the colorless tubes connecting
the yellow or orange fusiform nodes; spores smooth, fuscous or violet-
black, 7-9 fx. Plasmodium yellow to yellow-green.

A very handsome and common little species ; like the preceding, but
generally greenish yellow in color, and occasionally brilliantly orange
without a suggestion of green. Indeed, the color is so variable that
some authors have been disposed to discard the species entirely, inas-
much as the chief specific character is color.

The following varieties may be recognized :

Var. aurantium (Bull.) Lister, Mycetozoa 47, 1894 (SphcErocarpus
aurantius Bull., 1791; Slemonitis aurantia (Bull.) Gmel. 1791; Phy-
sarum aurantium (Bull.) Pers., 1801; Trichia aurantia (Bull.) DC,

92 THE MYXOMYCETES

1805; Physarum nutans var. coccineum Fr., 1829; Physarum striatum
var. aurantiacum Fr., 1829). This is a bright orange phase, arising
from an orange plasmodium. Brandza, who would restrict P. viride
to delicate yellow forms with long slender stalks and fusiform yellow
nodes, notes that the two forms never occur together and believes
that they represent distinct species. Common.

Var. incanum Lister, Mycetozoa 47, 1894 (Stemonitis bicolor Gmel.,
1791 ; Physarum luteum Pers. 1801 ; Trichia lutea DC, 1805). Yellowish
gray, with pale yellow nodes. Common.

Var. hinnuleum G. List., Jour. Bot. 62 : 17, 1924, from India, is
described as with fawn colored sporangia and nodes and buff spores.

Common and world-wide in its distribution.

74. Physarum bethelii {Macbr.) List.

Mycetozoa ed. 2. 57. 1911.

1899. Tihnadoche bethelii Macbr. in litt.

1913. Physarum viride Pers. var. bethelii Sturgis, Colo. Coll. Pub. Sc. Ser.
12 : 439.

Sporangia scattered, globose, umbilicate below, 0.5-1 mm. in diam-
eter, iridescent-blue, or sometimes tinged by the presence of delicate
pale yellow calcareous scales, stipitate; stipe rather short, black or dark
brown, equal; capillitium dense, radiating from the black, slightly in-
trusive summit of the stipe, and ascending from the base of the pe-
ridium; the nodules not numerous, elongate, branching betimes, pale
yellow; spores minutely roughened, 10-12 jx. Plasmodium yellow.

Both Miss Lister and Mr. Hagelstein agree with Dr. Sturgis in con-
sidering this merely a variety of P. nutans. Doctor Brandza believes it
distinct. The material at hand seems sufficiently distinct to justify
retaining it, pending fuller information.

This beautiful, delicately tinted little species is clearly tilmadochoid
in the Friesian sense. The capillitium persists after the fall of the upper
filmy peridium, adherent below to the persisting peridial base. Col-
lected thus far only by Professor Bethel and by Professor Sturgis,
Colorado, by Mr. Hagelstein in Long Island and by Professor Brandza
in Rumania.

75. Physarum rigidum G. Lister

Mycetozoa ed 3. 36. 1925.
1911. Physarum viride Pers. var. rigidum Lister, Mycetozoa ed. 2. 56.

Sporangia gregarious, stalked, lenticular, often umbilicate above,
yellow, dull orange or iridescent from absence of lime granules; stalk
slender, orange or yellow above, dark below from included refuse

CRATERIUM 93

matter, 0.3-1.5 mm. high; capillitium of sparingly branched threads
or flattened tubes with long narrow orange lime-knots, or consisting
almost entirely of slender, rod-like tubes enclosing yellow lime gran-
ules; spores rich violet-brown, minutely spinulose, 9-12 /u. Plasmodium
yellow.

The above description, based on that of Miss Lister, as well as the
fact that the species was formerly regarded as a variety of P. viride,
seems to justify placing it tentatively with the tilmadoches.

Reported from the West Indies; Central Africa, Malay Peninsula,
Japan.

5. Craterium Trentepohl
in Roth, Cat. Bot. 1 : 224. 1797.

Sporangia stalked, cyathiform, the peridium of two or three layers,
the dehiscence more or less definitely circumscissile, or by a distinct
lid, the upper portions calcareous, the lower cartilaginous, long-per-
sistent as a cup containing the spores and capillitium, the nodes of
the latter often aggregated to form a pseudocolumella.

Very close to Physarum, from which genus it is separated by the
form of the sporangia and the method of dehiscence. In some forms
there is a tendency to irregular dehiscence, notably in C. leucocephalum
var. scyphoides, but even here approximately half the sporangium wall
remains as a persistent cup. The capillitium is occasionally bad-
hamioid.

KEY TO THE SPECIES OP CRATERIUM

a. Dehiscence circumscissile or by the breaking up of the

upper wall of the sporangium b

a. Dehiscence by a distinct lid d

b. Sporangia violet or purple 1. C. paraguayense

b. Sporangia yellow 2. C. aureum

b. Sporangia white-capped c

c. Sporangia subglobose to obovoid 3. C. leucocephalum

c. Sporangia elongate, cylindrical 4. C. cylindricum

d. Capillitium entirely white 5. C. minutum

d. Lime-knots pale brown, small 6. C. concinnum

d. Lime-knots pinkish or reddish brown, some large 7. C. rubronodum

1. Craterium paraguayense (Speg.) List.

Mycetozoaed. 2. 95. 1911.
PI. VI, Figs. 129, 130.

1883. Didymium paraguayense Speg., Fung. Guar. Pug. 1 : 141.

1893. Craterium rubescens Rex, Proc. Ac. Nat. Sc. Phila. 370.

1904. Iocraterium rubescens (Rex) Jahn, Hedwigia 43 : 302.

1909. Iocraterium paraguayense (Speg.) Torrend, Fl. Myx. 174.

94 THE MYXOMYCETES

Sporangia gregarious, cylindrical or elongate-cyathiform, stipitate,
dark violet-red, the apex slightly roughened by pale calcareous gran-
ules, the peridium longitudinally wrinkled below; dehiscence irregularly
circumscissile; stipe darker, one-half the height of the sporangium,
longitudinally wrinkled; capillitium dense, abundantly calcareous;
spores violet-brown, minutely roughened, 8-9 jx.

In form resembling the following species, but instantly distinguished
by the color, which is red throughout, tinged with purple or violet.
The capillitium is badhamioid, as noted by Dr. Rex. Very distinct
from Physarum newtoni in color, form, habit, epispore, etc.

Iowa, Louisiana, Paraguay, Brazil.

2. Craterium aureum (Schum.) Rost.

Mon. 124. 1875.
PI. VI, Figs. 131, 132; PI. XXI, Figs. 570, 571.

1803. Trichia aurea Schum., Enum. PI. Saell. 2 : 207.

1829. Craterium mutabile Fries, Syst. Myc. 3 : 154, non Symb. Gast. 19, 1818.

1844. Cupularia mutabilis (Fr.) Rabenh., Deutsch. Krypt.-Fl. 1 : 271.

Sporangia gregarious, globose or obovoid, 0.4-0.6 mm. in diameter,
stipitate, golden yellow, erect, the peridial wall thin, especially at the
summit, where at maturity it breaks up somewhat reticulately, leav-
ing the persistent lower portion with an uneven margin above which
projects the pale yellow capillitium; stipe short, orange or brownish
red, arising from a small hypothallus; capillitium dense, yellow, the
nodules not large, irregular, tending to form a pseudocolumella in the
center of the cup; spores minutely war ted, violaceous brown, 8-10 fx.

Fries regarded this, which he called C. mutabile, the most distinctly
marked species of the genus; chiefly, as it appears, on account of the
bright yellow color. This, however, varies. Some specimens before us
are gray, showing only a trace of yellow below. In some European
specimens a reddish tinge prevails. The form of the sporangium also
varies. In typical specimens, unopened, the shape is almost pyriform;
opened, we have a cylindric, oftenest lemon-yellow vase, mounted on
a short striate stalk. But again, from the same plasmodium, we may
have globose sporangia, opening so as to leave only a shallow, salver-
shaped base. In this case the stipe is also longer. The plasmodium is
said to be "clear lemon yellow" (Massee).

There seems little doubt that Schumacher had in mind the present
species in his Trichia aurea. Rostafinski shows that Fries' synonym,
C. mutabile, is founded on a mistake. The earlier specific name is there-
fore on Rostafinski's authority adopted.

Not common. New York, New Jersey, Pennsylvania, North Caro-

CRATERIUM 95

Una, Ohio, Iowa, Colorado, Washington, California; Europe, Asia,
Africa.

3. Craterium leucocephalum (Pers.) Ditm.

in Sturm, Deutsch. Fl. Pilze : 121. 1813.
PL VII, Figs. 133, 134, 135.

1791. Stemonitis leucocephala Pers. in Gmel., Syst. Nat. 2 : 1467.

1795. Arcyria leucocephala (Pers.) Hoffm., Fl. Crypt. Germ. 2, pi. 6, fig. 1.

1821. Cyathus cinereus Purton, Midi. Flora 3 : 309.

1833. Cupularia leucocephala (Pers.) Link, Handb. Gewach. 3 : 421.

1833. Craterium xanthopus Walk., Fl. Crypt. Germ. 2 : 358.

1836. Craterium deoperculatum Fr. in Weinm., Hymen. & Gast. 597.

1844. Cupularia xanthopus (Wallr.) Rabenh., Deutsch. Krypt.-Fl. 1 : 271.

1889. Physarum scyphoides Cke. & Balf. ex Massee, Jour. Myc. 5 : 185.

1892. Craterium fuckelii Massee, Mon. 272.

1896. Craterium convivale (Batsch) Morg., Jour. Cin. Soc. Nat. Hist. 19 : 14.

Sporangia gregarious, short-cylindric or ovate, pure white above,
brown or reddish brown below, stipitate, occasionally sessile and some-
what plasmodiocarpous, dehiscence irregularly circumscissile, the
persistent portion of the peridium beaker-shaped; stipe short, stout, ex-
panded above into the base of the peridium, with which it is concolor-
ous; hypothallus scant; capillitium white or sometimes, toward the
center, brownish, the calcareous nodules large, conspicuous, and per-
sistent; spore-mass black; spores violaceous brown, minutely spinulose,
8-9 /*.

Distinguished by its white cap from all except the next, from which
the markedly different form serves as the diagnostic feature. In some
gatherings, curious patches of yellow mark the otherwise snow-white
cap and sides; these are mere stains, or sometimes definite, crystalline,
flake-like bodies, standing out in plain relief on the sporangial wall, or
lurking in the larger nodules which are massed along the axis of the cup
to form the pseudocolumella here strongly developed. Mr. Lister
calls attention to these yellow flakes, and regards them as diagnostic.
European specimens often show the capillitium more or less yellow,
sometimes throughout.

The nomenclature question is here somewhat difficult. Fries heads
his list of synonyms with Peziza convivalis Batsch. Batsch simply
described Micheli's figure. Now there is nothing in Micheli's figure
(pi. 86, fig. 14) to enable one to say with certainty which craterium
Micheli had in mind, if a craterium at all. Nor does Batsch help the
matter when he offers the description following: "Stipitata; acute-
conica, patens; stipite subdistincto, lineari, brevi, valido. Albicans.
Infoliis hedercE putridis." There is nothing definitive here but the one

96 THE MYXOMYCETES

word "albicans" quoted from Micheli. But this term is applicable
rather to C. minutum, the cups of which whiten with weathering. It
may be, as insisted by Fries (Syst. Myc. 3 : 149), that Micheli drew
crateriums; but if so, we cannot determine which species.

The specific name here adopted was applied by Persoon probably
to this form; but Persoon likewise failed to distinguish the present
species from C. minutum (see Syn. Meth. Fung., pp. 183, 184, and
Fries op. cit., p. 153). Ditmar leaves no doubt as to what he figures
and describes, and accordingly the name he first correctly uses is here
adopted.

The var. cylindricum of Lister is here regarded as a distinct species.
The variety rufum G. List, is entirely brownish red. Var. scyphoides
List, has turbinate or globose sporangia, the entire upper half fall-
ing away irregularly in dehiscence. The var. inclusum Cel. fil. (Myx.
Bohm. 79), with sporangia clustered on a common stalk, is reported
from central Europe.

Common. New England and Ontario to North Carolina, Washing-
ton and California, Brazil, Bolivia, Argentina. Common in Europe
and in the old world generally.

4. Craterium cylindricum Massee

Mon. 268. 1892.
PI. VII, Figs. 136, 137.

1894. Craterium leucocephalum (Pers.) Ditm. ex Lister, Mycetozoa 72, in part.
1911. Craterium leucocephalum (Pers.) Ditm. var. cylindricum List., Mycetozoa
ed. 2. 97.

Sporangia gregarious, 0.5 mm. in diameter or less, slender, cylindric,
almost entirely white, stipitate; peridium delicate, transparent al-
though calcareous nearly to the base, opening by a dehiscence regularly
circumscissile; stipe short, about one-third the total height, clear
orange-brown, somewhat furrowed, rising from an indistinct hypothal-
lus; capillitium very lax, physaroid, the calcareous nodules large,
rounded, pure white, aggregated at the center of the cup and often
forming a conspicuous pseudocolumella; spore-mass black; spore mi-
nutely roughened to practically smooth, violaceous brown, 8-9 fx.

Lister includes this species with C. leucocephalum, from which its
more delicate structure and cylindrical shape certainly distinguish it.
The dehiscence is even more regular than in the preceding species and
approaches that of C. minutum, with bleached forms of which it must
not be confused.

C. minimum Berk. & Curt., Grev. 2 : 67, 1873, has here priority,
but Massee regards this name as indicating a distinct species. We

CRATERIUM 97

have been unable to determine what the authors really had before
them, and adopt accordingly the first available combination.

New England and Ontario to Iowa and south; reported also from
Moldavia, Japan and the oriental tropics.

5. Craterium minuttjm {Leers) Fr.

Syst. Myc. 3 : 151. 1829.
PL VII, Figs. 138, 139, 140.

1775. Peziza minuta Leers, Fl. Herborn. 277.

1787. Cyathus minutus (Leers) Hoffm., Veg. Crypt. 6.

1797. Craterium pedunculatum Trent., in Roth, Cat. Bot. 1 : 224.

1803. Physarum turbinatum Schum., Enum. PL Saell. 2 : 205.

1803. Physarum pedunculatum (Trent.) Schum., Enum. PL Sasll. 2 : 205.

1813. Craterium vulgare Ditmar, in Sturm, Deutsch. Fl. Pilze 17.

1813. Craterium pyriforme Ditmar, in Sturm, Deutsch. Fl. Pilze 19.

1829. Craterium nutans Fr., Syst. Myc. 3 : 151.

1829. Craterium turbinatum (Schum.) Fr., Syst. Myc. 3 : 152.

1875. Craterium cerstedtii Rost., Mon. 120.

1875. Craterium friesii Rost., Mon. 122.

1892. Craterium confusum Massee, Mon. 263.

Sporangia scattered, gregarious, cyathiform or turbinate, grayish
brown or yellow, stipitate, the peridial wall rather thick, double,
opening by a distinct lid which lies usually below the slightly thickened
and everted margin of the cup; stipe paler, translucent, about equalling
in height the peridial cup, longitudinally wrinkled, with hypothallus
scant or none; capillitium physaroid, the calcareous nodules large,
white, and generally aggregated at the center of the cup; spore-mass
black, spores by transmitted light violaceous, minutely warted, 8-10 fx.
Plasmodium bright yellow to orange.

This is the most highly differentiated of the whole series. The cup
is shapely and well defined, while the lid is not only distinct, but is a
thin, delicate membrane of slightly different structure when compared
with the peridial wall. It is in most material before us depressed below
the mouth of the sporangium. The whole structure in such specimens
corresponds with Fries' description of C. pedunculatum Trent., while
specimens received from Europe correspond to Fries' account of
C. minutum Leers. Nevertheless we are assured that the two forms are
in Europe developed from the same Plasmodium, and therefore adopt
the earlier specific name as above. This is probably Peziza convi-
valis of Batsch and Micheli. Miss Currie reports the yellow phase
from Toronto and we have a number of yellow gatherings from Europe.

Common throughout the eastern United States and Canada, west
to Oregon and Washington, and south to Louisiana; cosmopolitan.

98 THE MYXOMYCETES

6. Craterium concinnum Rex

Proc. Acad. Nat. Sc. Phila. 1893 : 370.

Sporangia scattered, usually minute, broadly funnel-shaped, stipi-
tate, peridium simple, variously colored by innate lime granules, open-
ing by a regular cap or operculum, brownish white, darkest in the cen-
ter, always more or less convex; stipe equalling the cup in height, dark
brown, longitudinally ridged; capillitium a close-meshed network,
with small rounded or slightly angular masses of ochre-brown lime
granules, larger toward the center; spores pale brown, minutely
warted, 9-10 n.

This species differs from C. minutum, with which it seems most
nearly allied, in form, color, capillitium and color of spores. In habi-
tat, however, it seems no less distinct, being found mostly on the spines
of decaying chestnut-burs lying on the ground, in company with that
other peculiar species Lachnobolus globosus.

Eastern United States; Japan.

7. Craterium rubronodum G. Lister

Trans. Brit. Myc. Soc. 5 : 74. 1915.

1913. Badhamia rubiginosa (Chev.) Rost. var. concinna G. Lister in Minakata,
Bot. Mag. Tokyo 27 : 408.

Sporangia gregarious, stalked, goblet- or saucer-shaped, 0.2-0.6 mm.
in diameter, smooth, pearl gray with red-brown base; lid convex or
nearly flat, with an upturned rim, white or pinkish gray, smooth;
sporangium wall somewhat cartilaginous, pinkish gray with uniform
deposits of lime granules, studded on the inner side with many small
pouches containing lime; stalk dark red-brown, slender, 0.1-0.2 mm.
high, arising from a discoid hypothallus; capillitium of ovoid or irregu-
lar, rounded pale pink lime-knots, dark red-brown by transmitted
light, connected by hyaline threads, usually forming a large central
solid or hollow pseudocolumella; spores purplish gray, echinulate or
imperfectly reticulate, 10-12 /x. Plasmodium primrose yellow, then
orange.

The above description abridged slightly from Lister, ed. 3.

Japan, India.

6. Trichamphora Jungh.

Fl. Crypt. Jav. 12. 1838.

Sporangia discoidal, concave above, saucer-shaped, stipitate; pe-
ridium membranous, more or less encrusted with lime; capillitium

PHYSARELLA 99

colorless, with many or few lime-knots, sometimes almost badhamioid,
at other times limeless and in this respect approaching Didymium.

Rather artificially separated from Physarum, mainly on the basis of
the broad, saucer-shaped sporangium, mounted on a stalk. Unlike
Physarella in shape and lacking the characteristic trabecule of that
genus.

A single species:

Trichamphora pezizoidea Jungh.

Fl. Crypt. Jav. 12. 1838.
PI. VII, Figs. 141, 142.

1854. Didymium zeylanicum Berk., Hook. Jour. Bot. 6 : 230.

1869. Physarum macrocarpum Fuckel, Symb. Myc. 343.

1873. Trichamphora fuckeliana Rost., in Fuckel, Symb. Myc, Nachtr. 71,

1875. Chondrioderma pezizoides Rost., Mon. 424, pi. 8, fig. 122.

1876. Badhamia fuckeliana Rost., Mon. App. 2.

1876. Chondrioderma zeylanicum (Berk.) Rost., Mon. App. 15.

1876. Chondrioderma muelleri Rost., Mon. App. 15.

1876. Chondrioderma berkeleyanum Rost., Mon. App. 16.

1888. Didymium australe Massee, Grev. 17 : 7.

1892. Didymium pezizoideum (Jungh.) Massee, Mon. 239.

1899. Didymium parasiticum Sacc. & Syd., Syll. Fung. 14 : 836.

1903. Physarum pezizoideum (Jungh.) Pav. & Lag., Bull. Soc. Myc. Fr. 19 : 7.

Sporangia discoidal or saucer-shaped, gregarious, stipitate, erect
or nodding, grayish white, peridium thin, breaking irregularly, per-
sistent; stipe subulate, striate, reddish brown, transparent; capillitium
variable as above stated; spores pale violet-brown, spinulose or nearly
smooth, about 9 /jl.

In Mycetozoa ed. 3. 71, the spores are described as 9-17 /x in di-
ameter. This would seem to suggest incomplete development in the
sporangia with the larger spores.

Puerto Rico, British and Dutch Guiana, Bolivia; Europe, Africa,
Malay Peninsula, Australia, Japan; abundant in the old-world tropics,
apparently rare in the western hemisphere.

7. Physarella Peck
Bull. Torrey Bot. CI. 9 : 61. 1882.

Sporangia cylindrical, deeply umbilicate, the upper part of the
peridium inverted so as to form a thimble-shaped or bell-shaped struc-
ture; capillitium composed of slender filaments with minute fusiform
nodes, together with stout spine-like processes, extending from the
exterior to the interior walls of the sporangium and firmly attached to
the former.

100 THE MYXOMYCETES

The form of the sporangium in the only species is very variable, but
in typical cases is vasiform, the peridial wall at the apex introverted.
The capillitium is like that of Timadoche, except for the presence of
the "straight tubes" emphasized in the original description. These
are very remarkable and at once diagnostic. They take origin in the
sporangial wall and pass across to the "columella"; but at the de-
hiscence of the sporangium, in typical cases, they remain attached at
the points of origin, projecting as stout spine-like processes. The
formation of the capillitium has been studied by Bisby (1914).

Physarella oblonga {Berk. & Curt.) Morg.

Jour. Cin. Soc. Nat. Hist. 19 : 7. 1896.
PI. X, Figs. 223, 224, 225.

1873. Trichamphora oblonga Berk. & Curt., Grev. 2 : 66.

1873. Physarum rufibasis Berk. & Br., Jour. Linn. Soc. 14 : 85.

1875. Chondrioderma injlatum Rost., Mon. 425.

1876. Tilmadoche oblonga (Berk. & Curt.) Rost., Mon. App. 13.
1876. Tilmadoche Mans Rost., Mon. App. 14.

1882. Physarella mirabilis Peck, Bull. Torrey Bot. CI. 9 : 61.
1888. Tilmadoche minuta Berl., in Sacc, Syll. Fung. 7 : 361.
1892. Physarum Mans (Rost.) Massee, Mon. 296.

Sporangia scattered or gregarious, typically cup-shaped or sub-
infundibuliform, stipitate, erect or cernuous, but varying through low
salver-shaped cups, to irregular applanate and sessile masses; peridium
thin but firm, tawny, roughened by numerous yellowish calcareous
scales, at length ruptured above and often reflexed in the form of
petal-like segments from which project upwards the spine-like trabe-
cules of the capillitium; stipe when present long, terete, red, arising
from a scant hypothallus and extended within the sporangium to meet
the tubular pseudocolumella; capillitium of delicate violaceous threads
seldom branched or united, radiating from the columella with few
calcareous nodular expansions, but supported by stout, yellow, cal-
careous trabecules, running parallel to the capillitial threads, long ad-
herent to the sporangial wall; spores nearly smooth, globose, violet-
brown, 7-8 ix.

Not uncommon, usually in wet places. New York to South Dakota,
Washington, and Louisiana, Nicaragua, British Guiana, Brazil; re-
ported also from Ceylon, Java, Japan, Africa and the tropics generally.
Rare in Europe.

Whether the form described from Portugal as Physarella lusitanica
Torrend is a distinct species is not certain. It is small, stalked, some-
times subglobose and ovoid without pseudocolumella.

LEOCARPUS 101

8. Cienkowskia Rost.
Versuch9. 1873.

Fructification plasmodiocarpous, irregularly dehiscent, the wall a
thin cartilaginous membrane destitute of lime, except for the capillitial
attachments within; capillitium scanty but rigid, and characterized
everywhere by peculiar hook-like branchlets, free and sharp-pointed,
the spores as in Physarum.

The genus contains, so far, but a single species :

Cienkowskia reticulata (Alb. & Schw.) Rost.

Versuch9. 1873.
PI. VII, Figs. 143, 144, 145.

1805. Physarum reticulatum Alb. & Schw., Consp. Fung. 90.
1829. Diderma reticulatum (Alb. & Schw.) Fr., Syst. Myc. 3 : 112.

Plasmodiocarp an elongated, irregularly limited, close-meshed net,
closely applied to the substratum, the wall thin, transversely rugulose
and roughened, dull orange-yellow, splashed here and there with
scarlet, sometimes entirely red, within marked by transverse cal-
careous ridges, supporting in part the calcareous system of the cap-
illitium; capillitium of delicate, rigid, reticulating yellow tubules or
threads with numerous free, uncinate or sickle-shaped branchlets, and
large, irregular, calcareous plates, more or less transverse to the axis
of the sporangium, attached to the peridial walls, as if to form septa;
ordinary calcareous nodules few; spore-mass jet-black, spores by
transmitted light pale violaceous, minutely roughened, 9-10 fx. Plas-
modium deep brownish red.

Rare in the United States; easily recognized under the hand lens,
much more by the microscopic characters quoted; probably often over-
looked by the collector, as to the naked eye it presents the appearance
of some imperfectly developed, dried-up Plasmodium. Very unlike
Physarum serpula Morgan, not infrequently offered by collectors as
Cienkowskia. It is Diderma reticulatum of Fries, who, strangely
enough, thought it might be a plasmodial phase of Diderma verni-
cosum (i. e., Leocarpus fragilis) (Syst. Myc. 3 : 112).

Eastern United States and Ontario to Iowa, California; Europe,
Ceylon, Malay Peninsula, Java, Japan.

9. Leocarpus Link
Mag. Ges. Nat. Fr. Berl. 3 : 25. 1809.

Peridium double, the outer wall thick, smooth, polished, smooth
inside or with deposits of lime, the inner wall delicate, hyaline; cap-
illitium of two more or less distinct systems, the one a delicate network

102 THE MYXOMYCETES

of hyaline, limeless threads, the other calcareous throughout, or nearly
so, the meshes large and the threads or tubules broad; columella none;
pseudocolumella sometimes present.

This genus was by Link established on purely external characters.
Rostafinski supplemented Link's definition by calling attention to the
peculiar character of the capillitium and to the microscopic characters
in general. The outer peridium is thick and strong, unlike the ordinary
structure in Physarum. Some physarums, however, have a very similar
outer wall; P. brunneolum, for instance, or P. citrinellum. In dehiscence
and structure there is also some resemblance to some species of Did-
erma, and by Persoon and Fries the common species was so referred,
but the capillitium is again definitive.

A critical study of all these things really begins with Rostafinski.
Under his definition of the present genus P. albescens Ell. might well be
entered here. Such course at present would but increase confusion,
and until by future research the ontogeny of all these, and so their rela-
tionship, shall be more exactly known, the genus may be left with its
historic species, — monotypic.

Leocarpus fragilis (Dickson) Rost.

Mon. 132. 1875.
PL VII, Figs. 146, 147, 148.

1785. Lycoperdon fragile Dickson, PL Crypt. Brit. 1 : 25.

1795. Diderma vernicosum Pers., Ust. Ann. Bot. 15 : 34.

1797. Trichia lutea Trentep., Roth, Cat. Bot. 1 : 230.

1801. Lycogala parasiticum With., Br. PL 4 ed. 372.

1803. Spumaria ramosa Schum., Enum. PL Saell. 2 : 195.

1803. Physarum nitidum Schum., Enum. PL Saell. 2 : 205.

1803. Physarum vernicosum (Pers.) Schum., Enum. PL Saell. 2 : 206.

1804. Reticularia fragilis (Dicks.) Poir., Lam. Encycl. 6 : 183.

1809. Leocarpus vernicosus (Pers.) Link, Mag. Ges. Nat. Fr. Berl. 3 : 25.

1809. Leocarpus spermoides Link, Mag. Ges. Nat. Fr. Berl. 3 : 25.

1817. Leocarpus atrovirens Fr., Symp. Gast. 13.

1827. Leangium atrovirens Fr., Stirp. Femsj. 83.

1827. Leangium vernicosum (Pers.) Fr., Stirp. Femsj. 83.

1829. Diderma atrovirens Fr., Syst. Myc. 3 : 103.

1837. Tripotrichia elegans Corda, Icon. Fung. 1 : 22.

1849. Leocarpus ramosus Fr., Summ. Veg. Scand. 450.

1921. Liceopsis jurensis Meylan, Bull. Soc. Vaud. Sc. Nat. 53 : 459.

Sporangia gregarious or clustered, sessile or stipitate, globose, obovoid
or elongated, rusty or yellow, but occasionally deep reddish brown or
nearly white, shining; peridium opening at maturity in somewhat
stellate fashion; capillitium as described for the genus; stipe when

DIDYMIACE^E 103

present filiform, white or yellow, weak and short; spores dark, paler
at one side, coarsely warted, 12-14 ,u. Plasmodium orange-yellow.

Recognizable at sight by the form and color of the sporangia. In
shape and posture these resemble the eggs of certain insects, and,
occurring upon dead leaves, generally where these have drifted against
a rotten log, they might perchance be mistaken for such structures.
With no other slime molds are they likely to be confused. The outer
peridium opens irregularly, or more rarely stellately. At the center
of the capillitium there is sometimes a calcareous core.

A plasmodiform gathering of this species from California, which
might be mistaken for an entirely different thing, is yellow, sessile and
has adherent spores; looks like a badhamia; but is, after all, a leocarpus
and probably belongs here. The spores are irregularly clustered and the
badhamioid section of the capillitium seems to be dominant.

Throughout the world; common.

Family DIDYMIACE.E

Capillitium non-calcareous, simple or somewhat branched, but not
forming an intricate net; peridium or stipe, or both, more or less cal-
careous; lime on surface of peridium often in the form of stellate crys-
tals or crystalline disks, sometimes scanty, rarely lacking; spores
violaceous black in mass.

KEY TO THE GENERA OF THE DIDYMIACEjE

a. Calcareous deposits in the form of stellate crystals b

a. Calcareous deposits not stellate crystals c

b. iEthalioid 1. Mucilago

b. Plasmodiocarpous or sporangiate 2. Didymium

c. Peridium strongly and continuously calcareous d

c. Calcareous deposits not continuous; scattered; sometimes re-
stricted to basal portion; rarely lacking /

d. Lime on surface of peridium in form of cylindrical peg-like

protuberances 3. Physarina

d. Lime forming a granular or firm shell e

e. Peridium double; layers often distant 4. Diderma

e. Peridium single 5. Wilczekia

f. Calcareous deposits in the form of scattered, flattened scales 6. Lepidoderma
f. Calcareous deposits restricted to basal region, embedded in

a dark, granular deposit 7. Leptoderma

1. Mucilago Micheli ex A dans.
Fam. des PI. 2 : 7. 1763.
1791. Spumaria Pers., in Gmel., Syst. Nat. 2 : 1466.

Fructification aethalioid, consisting of a large pulvinate mass com-
posed of numerous branched and anastomosing tubes as in Fuligo, the

104 THE MYXOMYCETES

whole covered by a white, foam-like crust composed of stellate lime
crystals; inner peridium delicate; capillitium of slender, limeless
threads, more or less branched, terminating in the walls of the tubes
and marked with occasional swellings or thickenings.

By the descriptions offered by most authors, and especially by
Rostafinski's figures (Mon., pi. 9, fig. 158), a pronounced columella is
called for in the structure of Spumaria. The individual tubes rise
from a common hypothallus, and occasionally portions of this run up
and give the appearance of stipitate sporangia. Sometimes also this
upper extension of the hypothallus passes beyond or behind the base of
such a tube or between two or more, and is more or less embraced by
these in their confluent flexures. This, it seems, suggested Rostafinski's
elaborate diagram; at least, no other form of columella is shown by
American materials at hand.

A single species: —

Mucilago spongiosa (Leyss.) Morg.

Bot. Gazette 24 : 56. 1897.
PI. VII, Figs. 149, 150.

1783. Mucor spongiosus Leysser, Fl. Hal. 305.

1791. Reticularia alba Bull., Champ. Fr. 92.

1791. Spumaria mucilago Pers., in Gmel., Syst. Nat. 2 : 1466.

1805. Spumaria alba (Bull.) DC, Fl. Fr. 2 : 261.

1829. Didymium spumarioides Fr., Syst. Myc. 3 : 121, non Symb. Gast. 1818.

1833. Diderma spumariccforme Wallr., Fl. Crypt. Germ. 2 : 374.

^Ethalium white or cream colored, of variable size and shape, 1-7 cm.
in length and half as broad, the component tubes resting upon a
common hypothallus and protected by a more or less deciduous cal-
careous porous cortex; peridial walls thin, and where exposed, iri-
descent, generally whitened by a thin coating of lime crystals; cap-
illitium scanty, of simple, mostly dark colored, slightly anastomosing
threads; columella indefinite or none; hypothallus white, spongy;
spore-mass black; spores violaceous, exceedingly rough, large, 12-15 p.
Plasmodium creamy white.

The plasmodium is dull white, of the consistency of cream, and is
often met with in quantity on beds of decaying leaves in the woods.
In fruiting, the plasmodium ascends preferably living stems of small
bushes, herbaceous plants, or grasses, and forms the aethalium around
the stem some distance above the ground. The cortex varies in amount,
is also deciduous, so that weathered or imperfectly developed forms
probably represent the form described as Spumaria cornuta Schum.

Two varieties of this species are recognized; one from Bolivia, var.

DIDYMIUM 105

dictyospora described by R. E. Fries (Arkiv for Botanik 1 : 66) differs
from the type chiefly in its finer capillitial threads and its darker spores
with longer spines and fine reticulate sculpture; the other from Colo-
rado, var. solida Sturgis (= Spumaria solida Jahn) differs, as the name
implies, principally in its greater compactness and slightly smaller
calcareous crystals; a desert phase.

Common in the United States, especially east of the Rockies, South
America; Europe, Africa, Australia.

2. Didymium Schrad. emend. Fries
Syst. Myc. 3 : 113. 1829.
1797. Didymium Schrad., Nov. Gen. Plant. 20, in part.

Sporangia distinct, stipitate, sessile or even plasmodiocarpous, never
asthalioid; peridium thin, irregular in dehiscence, covered with a more
or less dense coating of calcareous crystals; columella more frequently
present; capillitium of delicate threads, simple or sparingly branched,
extending from the columella to the peridial wall.

The genus Didymium, as set up by Schrader, included a number of
species now assigned to Diderma, Lepidoderma or Lamproderma.
Fries set out the didermas; de Bary and Rostafinski completed the re-
vision by removing the remaining alien forms.

The genus is instantly recognized by the peculiar form of its cal-
careous deposits, stellate crystals coating, or merely frosting, usually
distinct sporangia.

KEY TO THE SPECIES OF DIDYMIUM

a. Lime crystals aggregated into discoidal, often concave

scales, sessile or plasmodiocarpous I. D. nivicolum

a. Lime crystals scattered or forming a powdery coating

on surface of peridium °

a. Crystals combined to form a shell-like crust *

b. Plasmodiocarpous c

b. Sporangiate /

c. Yellowish or tawny; spores dark, tuberculate, 12-15 fj. 2. D.fulvum

c. Pale brown or ochraceous; spores pale, smooth, 5-7 /x 3. D. ochroideum

c. Lime coat white; inner peridium usually dark »

d. Flattened, thin; capillitium bearing conspicuous

vesicles 4. D. complanatum

d. Capillitium not bearing vesicles e

e. Capillitium of vertical, tubular columns containing

crystalline lime 5. D. anomalum

e. Capillitium only slightly branched; columella lacking;
plasmodiocarps small; sometimes sporangiate, rarely
with a short stalk 6. D. anellus

106 THE^MYXOMYCETES

e. Capillitium dense, dark; plasmodiocarp very flat; spores

1 1-14 n 7. D. dubium

f. Sporangia sessile or nearly so; crust thick, fragile,

distant 8. D. crustaceum

f. Typically with distinct stipes g

g. Peridium usually depressed or lenticular, umbilicate

below *

g. Peridium subglobose or globose, not markedly um-
bilicate «

h. Spores irregularly reticulate; stipe often yellowish

or pinkish 9. D. intermedium

h. Spores nearly smooth to spiny or warted, but not

reticulate *

i. Stipe yellow or orange; peridium cartilaginous, yellow-
ish; lime often in scale-like clusters 10. D. leoninum

i. Stipe pale brown; peridium grayish buff; columella

yellowish, rough or spiny 11. D. eximium

i. Stipe white, fluted; fructification sometimes sessile or

plasmodiocarpous 12. D. squamulosum

i. Stipe very dark to black j

j. Sporangia greatly flattened, discoid 13. D. clavus

j. Less compressed, large, over 0.5 mm. in diameter;

capillitium dark, coarse 14. D. melanospermum

j. Smaller; capillitium pale, delicate 15. D. minus

k. Stipe dark brown to black; columella dark, often nearly

obsolete 16. D. nigripes

k. Stipe yellow to yellow-brown; columella white or pallid 17. D. xanthopus
I. Sessile or short-stalked; ochraceous or yellowish

white; columella very large, pulvinate 18. D. vaccinum

I. Broadly plasmodiocarpous, depressed and very thin;

peridium tending to break away as a whole 19. D. listeri

1. Sessile, pulvinate to plasmodiocarpous *»

m. Spores nearly smooth, 12-14 fx 20. D. dijjorme

m. Spores very dark, rough, obscurely banded and sub-
reticulate, 12-15 /x; peridium diderma-like, the crystals
obscure 21. D. quitense

m. Spores with short spines, often clustered, sometimes

with reticulate patches, 9-10 ;u 22. D. trachysporum

1. Didymium nivicolum Meylan

Bull. Soc. Vaud. Sc. Nat. 57 : 40. 1929.
PI. VIII, Fig. 177.

1925. Didymium wilczekii Meylan ex G. List., Mycetozoa ed. 3. 120, in part.

Sporangia sessile, subglobose, 1-1.5 mm. broad, or plasmodiocarpous,
white; internal layer of peridium very thin, transparent, covered with a
more or less pulverulent mass of lime crystals aggregated into concave
or discoid scales; capillitium of rather rigid, anastomosing pale purplish
to pallid threads, bearing occasional nodules and swellings; columella

DIDYMIUM 107

yellowish, poorly developed or obsolete; spores dark blackish purple,
almost opaque, distinctly and coarsely spiny, 12-15 p.

The scaly outer wall is distinctive. A collection submitted by
M. Meylan is certainly distinct from D. dubium (= D. wilczekii).

Swiss Alps.

2. Dedymium fulvum Sturgis

Mycologia 9 : 327. 1917.
PL VIII, Fig. 175.

Sporangia gregarious, sessile, elongate or forming curved plasmodio-
carps, sometimes confluent, rarely subglobose, concave beneath, pale
raw umber in color, 0.5-0.8 mm. in width, occasionally seated on a
concolorous, membranous, lime-encrusted hypothallus which may form
pseudo-stalks; sporangium wall membranous, stained with yellow
blotches, thickly sprinkled with clusters of large acicular crystals of
pale yellowish lime; columella very much flattened or obsolete; cap-
illitium an abundant network of delicate, almost straight or flexuose,
pale purple or nearly hyaline threads, frequently with dark, calyciform
thickenings as in Mucilago, and occasionally showing fusiform, crystal-
line blisters; spores dark purplish brown, coarsely tuberculate, the
tubercles usually arranged in curved lines, paler and smoother on one
side, 12.5-14.5 /*.

Colorado.

3. Dedymium ochroedeum G. Lister

Jour. Bot. 69:297. 1931.

Sessile, pulvinate or forming slender plasmodiocarps 0.5 mm. broad,
pale brown or ochraceous, slightly grooved; wall pale orange, thickly
clothed with stellate crystals, sometimes divided into small areolae,
each with a darker raised center to which a crystal adheres; hypothallus
scanty, yellowish red; floor orange colored with scanty deposits of
lime forming a low columella; capillitium a loose network of slender,
pale purplish threads; spores pale purplish gray, nearly smooth, 5-7 /*.

Resembling D. fulvum, differing in the more slender plasmodiocarps,
the delicate capillitium and the small, pale, nearly smooth spores.

New York; India, Japan.

4. Dedymium complanatum (Batsch) RosL, non Fuck. 1869

Mon. 151. 1875.
PI. VII, Figs. 151, 152, 153.
1786. Lycoperdon complanatum Batsch, Elench. Fung. Cont. 1 : 251.

Fructification plasmodiocarpous, creeping, flattened, thin, vein-like,
annulate or reticulate, the dark colored peridium covered with white,

108 THE MYXOMYCETES

but not numerous, crystals; hypothallus none; columella none; capil-
litium of much branched, violaceous threads combined to form a
rather dense net which bears numerous, peculiar, rounded vesicles,
yellowish in color, 30-50 /jl in diameter; spores minutely warted, 7-9 /i,
pale violaceous brown. Plasmodium greenish yellow.

The defining characteristics here are the curious supplementary
vesicles which are visible as brown knots under a hand lens. These are
attached to and penetrated by the neighboring capillitial threads,
withal warted like a spore. They suggest the curious spore-like but
giant cells found in the stipes of some arcyrias. Rostafinski gives them
abundant consideration, illustrating them on pi. 9, figs. 166 and 180,
of the Monograph, although in the explanation of the plate he has
strangely confused the species with Didymium crustaceum Fr. Under
Didymium serpula, Fries may refer to the present species, although
there is nothing in his description to determine the fact. The same
thing may be said of the description and figures of Batsch. Rostafinski,
in the Monograph, seems to have been satisfied as to the identity of
Batsch's materials: in the Appendix, he writes D. serpula, but gives
no reason.

Rare. New York, Pennsylvania (?), Iowa; Europe.

5. Didymium anomalum Sturgis

Colo. Coll. Pub. Sc. Ser. 12 : 444. 1913.

Plasmodiocarp gray, very thin, effused, 2-10 mm. long; wall single,
membranous, hyaline or yellowish with rather scanty deposits of small,
stellately crystalline or amorphous lime; columella none; capillitium
consisting entirely of straight, membranous, tubular columns, extend-
ing from the base to the upper wall of the plasmodiocarp, 7-22 /* thick
and usually containing small crystalline masses of lime; spores bright
violet-brown, minutely and irregularly spinulose, 10.5-11.5 ju.

The original description gives the length of the plasmodiocarps as
2-10 cm. In our material, from Dr. Sturgis, and evidently a portion
of the type collection, there are two plasmodiocarps 3-4 mm. in length,
and a couple of smaller ones, less than 1 mm. Presumably "cm."
was written in error. The description of the thickness, as "less than
1 mm." is misleading. They are exceedingly thin, perhaps 0.1-0.2 mm.
Nevertheless the curious peg-like capillitial columns may readily be
seen under a binocular.

Massee transferred Rostafinski's Chondrioderma anomalum to Di-
dymium as D. anomalum. Lister thinks these names may be synonyms
of D. squamulosum. Whatever they may represent, Sturgis' name
would seem to be preoccupied, and may have to be changed. The

DIDYMIUM 109

species is so different from other didymiums that it may have to be
placed in a distinct genus. Pending further study it seems unnecessary
to rename it.

Rare. Iowa, Montana, Colorado, Pennsylvania; England.

6. Didymium anellus Morgan

Jour. Cin. Soc. Nat. Hist. 16 : 148. 1894.
PI. VIII, Figs. 156, 157, 158.

Plasmodiocarp in small rings or links, often confluent and elongated,
irregularly connected, bent and flexuous, resting on a thin venulose
hypothallus, or sometimes globose, the peridium dark colored, with a
thin layer of stellate crystals, dehiscing in more or less circumscissile
fashion; capillitium of slender, dark colored threads, which extend
from base to wall, more or less branched, and combined into a loose
net; columella a thin layer of brown scales; spores globose, very
minutely warted, violaceous, 7-10 /jl.

This minute species resembles a poorly developed, or sessile, phase
of D. melanospermum. Some of the fructifications are spherical; such
may show a very short dark stalk. The columella is usually lacking
and the spores are much smaller than those of D. melanospermum.
The original description reads "irregularly dehiscent." The tendency
toward a circumscissile dehiscence, referred to in the English mono-
graph, is apparent in specimens collected by the author of the species
in Ohio in 1893.

Ohio, Iowa, Colorado, New Mexico, California; Europe, southern
Asia.

7. Didymium dubium Rost.

Mon. 152. 1875.
1908. Didymium wilczekii Meylan, Bull. Soc. Vaud. Sc. Nat. 44 : 290.

Fructification plasmodiocarpous, white or grayish white, flat and
thin, 2-16 mm. long and up to 6 mm. wide; peridium double, the
outer layer composed of rather loosely compacted crystalline cal-
careous granules, the inner layer tough and membranous, tawny
plumbeous; columella scanty or none; capillitium of rather thick brown
threads vertically arranged, 270-300 n long, sparingly united laterally
and occasionally forking, especially above; spores dark violet, distinctly
warted, 11-14 fx.

Mainly a mountain form. Small plasmodiocarps with firm shell-
like peridium and smaller and smoother spores collected in Iowa are
now referred to D. listeri.

Colorado; Europe.

110 THE MYXOMYCETES

8. DlDYMIUM CRUSTACEUM Fr.

Syst. Myc. 3 : 124. 1829.
PL VIII, Fig. 176.

1875. Didymium confluens (Pers.) Rost., Mon. 164.

Sporangia closely aggregated, globose, or by compression deformed,
sessile, snow-white by virtue of the remarkably developed covering
of calcareous crystals by which each sporangium is surrounded as if
to form a crust; peridium membranous, colorless, usually shrunken
above and depressed; columella pale, small, or obsolete; hypothallus
scant or vanishing; capillitium of rather stout violaceous threads
seldom branched except at the tips, where they are pale and often
bifid, or more than once dichotomously divided; spores strongly warted,
globose, violet-brown, 10-13 /jl.

This species has in some ways all the outward seeming of a diderma,
but cannot be referred to that genus because of the crystalline char-
acter of its crust. This is a very marked structure; loosely built up of
very large crystals, it is necessarily extremely frail, nevertheless per-
sists, arching over at a considerable distance above the peridium
proper. Sometimes, however, caducous, evanescent.

The sporangia are said to be sometimes stipitate. This feature
does not appear in any of the material before us. The hypothallus
is sometimes noticeable under some of the sporangia where closely
crowded, but is not a constant feature.

Rostafinski (Mon. 164) seems to have confused this species with
Persoon's Physarum confluens. In the Appendix he substitutes the
Friesian nomenclature. Persoon's description of his species is insuffi-
cient, and throws no light on the problem whatever.

Rare. Canada, Iowa, South Dakota, Colorado, Washington, Bolivia;
Europe, Japan.

9. Didymium intermedium Schroeter

Hedwigia 35 : 209. 1896.
1902. Didymium excelsum Jahn, Ber. Deutsch. Bot. Ges. 20 : 275.

Sporangia clustered or gregarious, discoidal and umbilicate be-
low, or lobed or convolute, grayish white, stipitate; stipe pale yellow,
tapering upwards, stuffed with lime crystals, expanding into the yel-
lowish, discoidal, recurving columella; capillitium colorless, more or
less branching; spores dark purple-brown, irregularly reticulate, 9-12 ji.

Differs from D. squamulosum mainly in the reticulate epispore and
the structure of the stalk. A collection from southern California
(O. A. Plunkett 178) determined as this species by Miss Lister, has

DIDYMIUM 111

dull pinkish stipes and very dark spores covered with coarse, capitate
spines and a coarse and irregular reticulum.
California, Brazil; Japan.

10. Didymium leoninum Berk. &* Br.

Jour. Linn. Soc. 14 : 83. 1873.

1876. Lepidoderma tigrinum (Schrad.) Rost., Mon. App. 23, in part.
1909. Lepidodermopsis leoninus (Berk. & Br.) Hohn., Sitzungsb. Akad. Wiss.
Wien, Math.-Nat. Kl. 118 (1) : 439.

Sporangia gregarious, subglobose or flattened, stipitate, the wall
cartilaginous, yellowish, covered more or less completely with white
or yellowish deposits of crystalline lime; stipes short, orange or brown,
containing lime, enlarged to form the globose orange columella and
often connected at base by a venulose hypothallus; capillitium of
slender anastomosing threads, colorless at the tips; spores violet-gray,
minutely warted, 7-9 /*.

Not unlike Lepidoderma tigrinum, but with stellate crystals and
smaller spores. The scale-like clusters in which the crystals may occur
led Hohnel to propose for this species a new genus intermediate between
Didymium and Lepidoderma.

Southern Asia and Japan.

11. Didymium eximium Peck

Rept. N. Y. State Mus. 31 : 41. 1879.

1892. Didymium fulvellum Massee, Mon. 237.

1925. Didymium nigripes Fr. var. eximium (Peck) Lister, Mycetozoa ed. 3. 116.

Sporangia scattered, dull grayish yellow or gray, depressed-globose,
umbilicate, minute, stipitate; peridium comparatively thick, tenacious,
especially persistent below, tawny or yellow; stipe pale brown or
orange, erect, even or slightly enlarged at base; hypothallus scant or
none; columella prominent, more or less discoidal, rough or spinulose,
especially on the upper surface, yellow or pallid; capillitium not
abundant, pale fuliginous, often branching and anastomosing to form
a loose net; spores nearly smooth, dark violaceous by transmitted
light, 8.5-9.5 ix.

The species differs from D. xanthopus in several particulars — in the
much firmer, more persistent and less calcareous peridium with a
distinct yellowish cast, in the more complex capillitium, in the darker
and larger spores and especially in the peculiar and prominent col-
umella, which is not only rough, but even "sometimes spinulose even
to the extent of long spicules penetrating to one-third the height of
the sporangia."

112 THE MYXOMYCETES

As stated under D. nigripes, this species and D. xanthopus are
called varieties only of nigripes. They are so retained in Mycetozoa,
3rd edition. Since, however, they are the usual presentation of the
species in the United States, it seems wise to let them stand for the
present, as here. They are quite distinguishable; D. eximium especially
well marked.

Apparently rare, it yet ranges from New York to Iowa, in rather
large colonies. Also Europe, Ceylon, Java.

12. Didymium squamulosum {Alb. & Schw) Fr.

Symb. Gast. 19. 1818.
PI. VIII, Figs. 159, 160, 161, 162, 163.

1805. Diderma squamulosum Alb. & Schw., Consp. Fung. 88.

1815. Licea stipitata DC, Fl. Fr. ed. 2. 101.

1815. Didymium efiusum Link, Mag. Ges. Nat. Fr. Berl. 7 : 42.

1817. Trichia pedicellata Poiret, Lam. Encycl. 13 : 373.

1827. Cionium squamulosum (Alb. & Schw.) Spreng., Syst. Veg. 4 : 529.

1829. Didymium costatum Fr., Syst. Myc. 118.

1829. Didymium herbarum Fr., Syst. Myc. 120.

1830. Physarum liceoides Duby, in DeCandolle, Bot. Gall. ed. 2. 2 : 461.
1869. Didymium radiatum Berk. & Curt., Jour. Linn. Soc. 10 : 348.
1873. Didymium neglectum Berk. & Br., Jour. Linn. Soc. 14 : 83.

1873. Didymium fuckelianum Rost., in Fuckel, Symb. Myc, Nachtr., 73.

1875. Didymium macrospermum Rost., Mon. 161.

1875. Didymium discoideum Rost., Mon. 162.

1876. Chondrioderma cookei Rost., Mon. App. 17.

1876. Physarum tussilaginis Berk. & Br., Ann. Mag. Nat. Hist. 4 ser. 17 : 139.

1879. Didymium angulatum Peck, Rept. N. Y. State Mus. 31 : 41.

1888. Didymium cookei (Rost.) Raunk., Bot. Tidssk. 17 : 86.

1888. Didymium affine Raunk., Bot. Tidssk. 17 : 88.

1891. Didymium bonianum Pat., Jour, de Bot. 5 : 316.

1892. Didymium tussilaginis (Berk. & Br.) Massee, Mon. 244.

Sporangia in typical forms gregarious, globose or depressed-globose,
usually stipitate, 0.5-1 mm. in diameter, but ranging through com-
pletely sessile and more or less fused sporangia to plasmodiocarps ;
peridium a thin iridescent membrane covered more or less richly with
minute crystals of lime; the stipe, when present, snow-white or rarely
yellowish to orange, fluted or channelled, stout, even; columella white,
conspicuous; hypothallus usually small or obsolete; capillitium of
delicate branching threads, usually colorless or pallid, sometimes
with conspicuous calyciform thickenings; spores violaceous, minutely
warted or spinulose, often with clusters of coarser and darker spines,
8-1 1 (x. Plasmodium yellow.

This, one of the most beautiful species in the whole series, is re-

DIDYMIUM 113

markable for the variations which it presents in the fruiting phase.
The hypothallus, sometimes entirely wanting, is anon well developed,
even continuous, venulose, from stipe to stipe. The capillitium varies
much in abundance as in color; when scanty, it is colorless and in every
way more delicate, when abundant, darker in color and sometimes
with conspicuous thickenings.

D.fuckelianum Rost., as shown in N. A. F. 2090, and in some private
collections, seems to be a rather stout phase of this species; the stipe
is more abundantly and deeply plicate, is sometimes tinged with brown,
and the capillitium is darker colored and coarser than in what is here
regarded as the type of the species; but withal the specimens certainly
fail to meet the requirements of Rostafinski's elaborate description
and figure (Mon. 161, fig. 134).

D. ejfusum Link probably stands for a sessile form of this species,
but Link's brief description is antedated by the much better one of
Albertini and Schweinitz.

Nicaragua specimens not only show a continuous vein-like hypo-
thallus, but have the peridia often confluent, the columellae in such
cases confluent, the stipes distinct. Furthermore, the largest spores
reach the limit of 12.5 /*, and perhaps the larger number range from
10-12.5 ju, and all are very rough. This corresponds with D. macrosper-
mum Rost., which is distinguished, says the author (Mon., p. 162),
"chiefly by the large and strongly spinulose spores." However, the
same sporangia in our Central American specimens yield spores 9.5-
12.5 ix, a remarkable range, so that D. macrospermum, on this side
of the ocean, at least, cannot be distinguished from D. squamulosum,
so far as spores are concerned. A similar remark may be made rela-
tive to the form of the columella which Rostafinski, in his figures
especially, would make diagnostic. The columella in the sporan-
gium with largest and roughest spores is that of a perfectly normal
D. squamulosum.

Cosmopolitan. Generally distributed throughout the wooded regions
of North America, from New England to Nicaragua, and from Canada
to California, West Indies, Bolivia, Brazil, Argentina. Not uncom-
mon about stable-manure heaps, in flower beds, and on richly manured
lands.

Var. daviforme Sturgis, Colo. Coll. Pub. Sc. 12 : 27, 1907 (= D. an-
nulatum Macbr., N. A. Slime-Moulds ed. 2. 125. 1922) is a small
delicate phase, 0.4-0.6 mm. in diameter, with a deeply umbilicate or
annulate sporangium and a reduced columella. The spores are slightly
smaller than in the typical form, 8-10 {x, and the clustered spines more
noticeable. While at times it seems quite distinct, it is perhaps too

114 THE MYXOMYCETES

close to certain small developments of the typical form to warrant
specific recognition.

Colorado, Oregon, Washington; Germany.

13. Didymium clavus (Alb. & Schw.) Rabenhorst

Deutsch. Krypt. El. 1 : 280. 1844.
PI. VII, Figs. 154, 155.

1805. Physarum clavus Alb. & Schw., Consp. Fung. 96.

1829. Didymium melanopus Fr., Syst. Myc. 3 : 114.

1873. Didymium commutabile Berk. & Br., Jour. Linn. Soc. 14 : 83.

1892. Didymium radiatum Berk. & Curt, ex Massee, Mon. 229, in part.

1892. Didymium neglectum Massee, non Berk. & Br., Mon. 231.

1899. Didymium masseeanum Sacc. & Syd., Syll. Fung. 14 : 836.

Sporangia gregarious, pale gray, discoid or pileate, depressed, stipi-
tate; peridium dark colored, frosted with calcareous crystals above,
naked below; stipe short, slender, tapering upward, furrowed, black,
arising from a more or less distinct hypothallus; columella obsolete;
capillitium of delicate threads, pale or colorless, little branched; spores
violaceous, pale, nearly smooth, 6-8 fx. Plasmodium gray.

This species is well differentiated, easy of recognition by reason of
its peculiar discoid sporangium, calcareous above, naked and black
beneath. D. neglectum Massee, reported from Philadelphia, is said
to be a slender form of the present species. The figures of Albertini
and Schweinitz are excellent, as is their description.

Occasionally collections occur in which the spores are distinctly
warted, with clusters of darker warts scattered over the surface.
These seem otherwise to be typical. Hohnel (1909) believes that
D. commutabile is a related but distinct species, characterized by a
long, white or yellowish and strongly encrusted stipe and by smaller
spores, 5-6 /x in diameter.

Pennsylvania, Wisconsin, Ohio, Iowa, Washington, Bolivia, Brazil,
Argentina; Europe, Africa, East Indies, Japan and the tropics gener-
ally. Not common in the United States.

14. Didymium melanospermum (Pers.) Macbr.

N. A. Slime-Moulds 88. 1899.
PI. VIII, Figs. 164, 165.

1794. Physarum melanospermum Pers., Roem. N. Mag. Bot. 1 : 88.

1797. Didymium far inaceum Schrad., Nov. Gen. PI. 22.

1797. Trichia compressa Trentep., Roth, Cat. Bot. 1 : 229.

1797. Trichia depressa Trentep., Roth, Cat. Bot. 1 : 231.

1799. Trichia sphcerocephala Sow., Engl. Fung. 240.

1801. Physarum farinaceum (Schrad.) Pers., Syn. Meth. Fung. 174.

DIDYMIUM 115

1808. Trichia farinosa Poiret, in Lam. Encycl. 8 : 53.

1809. Physarum sinuosum Lk., Mag. Ges. Nat. Fr. Berl. 3 : 27.
1809. Physarum capitatum Lk., Mag. Ges. Nat. Fr. Berl. 3 : 27.

1817. Strongylium minus Fr., Symb. Gast. 9.

1818. Didymium physaroides Fr., Symb. Gast. 21.
1827. Cionium lobatum Spreng., Syst. Veg. 4 : 529.

1833. Cionium far inaceum (Schrad.) Link, Handb. 3 : 410.
1889. Didymium fairmani Sacc, Jour. Myc. 5 : 78.

Sporangia gregarious, hemispheric, depressed, 0.6-1 mm. in diameter,
umbilicate below, stipitate or sessile; peridium firm, dull brown in
color, frosted with minute crystals of lime, breaking irregularly; stipe,
when present, short, stout, dull black, opaque, fluted, arising from a
broad base or hypothallus; columella large, prominent, dark colored,
rough above, concave below; capillitium of more or less sinuous,
usually dark colored threads, sparingly branched, and often with
calyciform thickenings; spore-mass black, spores by transmitted light
purple, spinulose or rough, 11-14 p.

A well-marked and common species, distinguished by its depressed
sporangium and dark colored, opaque stipe. The latter is usually
very short, almost completely concealed in the concavity of the um-
bilicate sporangium. The columella is dark colored, forming the
floor of the peridial cavity.

New England to Washington and Alabama, West Indies, Bolivia,
Brazil; Europe, Africa, Java.

15. Didymium minus Morgan

Jour. Cin. Soc. Nat. Hist. 16 : 145. 1894.
PI. VIII, Figs. 166, 167.

1892. Didymium farinaceum Schrad. var. minus Lister, Mycetozoa 97.
1925. Didymium melanospermum Macbr. var. minus Lister, Mycetozoa ed.
3. 115.

Sporangia gregarious, depressed-globose, umbilicate below, whitish
or gray, small, about 0.5 mm. in diameter, stipitate; stipe erect, rather
slender, black, faintly striate, usually equalling the diameter of the
sporangium in length, sometimes shorter, rarely lacking; columella
distinct, dark brown, globose or depressed-globose, attaining about the
center of the sporangium, rough; capillitium delicate, almost colorless,
radiating, sparsely branched; spores in mass black, by transmitted
light violet, minutely warted, 8-11 jx.

Distinguished from D. melanospermum by the smaller size, the less
flattened sporangium, the smoother and usually less limy peridium, the
longer stem and the smaller, paler, less strongly warted spores; from

116 THE MYXOMYCETES

D. nigripes by the shorter, thicker stem and the somewhat flattened
and more distinctly umbilicate sporangium.

New England to Alabama and Nebraska, Washington; Europe,
Africa, Java, Japan, probably cosmopolitan.

16. Didymium nigripes (Link) Fr.

Syst. Myc. 3 : 119. 1829.
PI. VIII, Figs. 168, 169.

1809. Physarum nigripes Link, Mag. Ges. Nat. Fr. Berl. 3 : 27.

1818. Physarum microcarpon Fr., Symb. Gast. 23.

1846. Didymium porphyropus Dur. & Mont., Fl. Alg. 409.

1875. Didymium microcarpon (Fr.) Rost, Mon. 157.

1888. Didymium tenue Pat., Bull. Soc. Myc. Fr. 4 : 96.

Sporangia gregarious, globose or hemispherical, 0.3-0.5 mm. in
diameter, umbilicate beneath, white, stipitate; peridium smoky, cov-
ered with minute calcareous crystals; columella dark; stipe slender,
erect, black, opaque; hypothallus scutate, black; columella distinct,
globose, black or dark brown; capillitium of delicate threads, pale
brown or colorless, with occasional brown thickenings or nodes, spar-
ingly branched; spores pale, violaceous by transmitted light, minutely
warted, 7-10 /x.

Rostafinski adopted Fries' name microcarpon simply because he
thought it more appropriate. Fries describes the columella "none
or . . . black." It is doubtful whether we have the typical Friesian
form on this continent. The fructification is in our specimens small,
about 0.4 mm., and the spores, as noted by Morgan, small; other-
wise the species is very close to D. xanthopus. Lister regards both
D. xanthopus and D. eximium as merely varieties of nigripes.

New York, Ohio, Wisconsin, Iowa, Washington, Puerto Rico,
British Guiana, Bolivia, Argentina. Cosmopolitan.

17. Didymium xanthopus {Ditmar) Fr.

Syst. Myc. 3 : 120. 1829.
PI. VIII, Figs. 170, 171.

1817. Cionium iridis Ditmar, in Sturm, Deutsch. Fl. 3 : 13.

1817. Cionium xanthopus Ditmar, in Sturm, Deutsch. Fl. 3 : 37.

1829. Didymium iridis Fr., Syst. Myc. 3 : 120.

1829. Didymium pertusum Berk., in Sm. Eng. Fl. 5 (2) : 313.

1873. Didymium proximum Berk. & Curt., Grev. 2 : 52.

1892. Didymium microcarpon (Fr.) Rost. ex Macbride, Nat. Hist. Bull. Iowa

2 : 146, in part.
1892. Didymium elegantissimum Massee, Mon. 243.
1925. Didymium nigripes Fr. var. xanthopus (Ditm.) Lister, Mycetozoa ed.

3. 116.

DIDYMIUM 117

Sporangia gregarious, white, globose, slightly umbilicate, stipitate;
peridium thin, and nearly or quite colorless, frosted with crystals of
lime; stipe yellowish or yellowish brown, corneous, erect, subulate,
slender; hypothallus none; columella pale or white, turbinate, globose
or depressed-globose; capillitium of dull brown or colorless threads
more or less branched, always white at the tips; spores violaceous,
nearly smooth, 7-9 fj,.

This seems to be the most common form in the United States. It is
distinguished from the preceding by the longer, more delicate, generally
orange-yellow stem with pale or white columella. N. A. F. 412 and 2089
are examples of D. xanthopus. The columella in blown-out specimens
is very striking, well confirming the diagnosis of Fries, "valde pro-
minens, globosa, stipitata, alba." Berkeley makes the color of the
capillitium diagnostic of D. proximum, but this feature is insufficient.

As noted in the synonymy, in the Lister monograph this is regarded
as merely a variety of D. nigripes. This view is confirmed to some
extent by the studies of Miss Cayley (1929) who grew both forms in
artificial culture and found that the color of the stalks was inconstant,
varying with the amount of coloring matter in the substratum. She
states, however, that the columella in the xanthopus cultures was
always white, and suggests that some of the confusion is due to the
occurrence of hybridization between the two forms, and possibly
between them and D. eximium. Skupienski (1930) grew D. nigripes
in pure culture and found that when the plasmodium fruited at 8-10° C.
typical sporangia were produced, while when the same plasmodium
fruited at 18-20° C. the sporangia resembled those of D. xanthopus,
although both spores and capillitium were abnormal. Intermediate
forms undoubtedly occur, but as a rule the collections as brought in
from the field are easily distinguishable. The species may be recog-
nized tentatively pending fuller information.

Cionium iridis Ditm., cited by Fries, apparently appeared before
C. xanthopus. If the synonymy should be confirmed, and the species
continue to be recognized, the name iridis takes precedence.

Common in the eastern United States and the Mississippi valley,
also Washington, Nicaragua, Bolivia, Argentina; Europe, Africa,
Ceylon, Java, Japan. Generally distributed in temperate regions.

18. Didymium vaccinum (Dur. &° Mont.) Buchet

Bull. Soc. Myc. Fr. 36 : 110. 1920.

1846. Diderma vaccinum Dur. & Mont., Expl. Sc. Alg. 407.
1875. Chondrioderma vaccinum (Dur. & Mont.) Rost., Mon. 180.
1898. Didymium trochus List., Jour. Bot. 36 : 164.

118 THE MYXOMYCETES

Sporangia plasmodiocarpous, hemispherical or turbinate, sessile or
very short-stalked, cream colored or white; peridium double, the outer
shell-like, the inner membranaceous, more or less adherent to the
outer, both caducous together, leaving the thickened base surrounding
an expanded columella; stipe, when present, very short, stout; capilli-
tium colorless, nearly simple; spores brownish purple, strongly warted,
9-10 /x.

On straw, decaying leaves, especially succulents such as Agave,
and on decaying cactus stems.

Said to be common in England, occurring also in Portugal, Algeria,
Japan. The only American collection thus far seems to be one made by
Bethel, at Monrovia, California, on the usual substrata.

19. Didymium listeri Massee

Mon. 244. 1892.
1894. Didymium dubium Rost. ex Lister, Mycetozoa 95, in part.

Plasmodiocarp pulvinate-compressed, thin, occurring in irregular
scattered patches 3-7 mm. in extent; outer wall white, shell-like,
covered with a powdery layer of stellate crystals, the inner peridium
delicate, membranous, dark, adherent, the whole tending to break
away entire, leaving the mass of spores and capillitium exposed;
columella none; capillitium dense, threads parallel, rarely over 200 n
long, branching acutely and dichotomously and connected by trans-
verse bars, dark brown, the tips paler; spores globose, dingy lilac,
minutely warted, 8-11 ix.

Formerly confused with D. dubium Rost., which, however, has much
larger spores and a different peridium. See that species, also Journal
of Botany 64 : 226, 1926.

Iowa, Bermuda; Great Britain, Germany.

20. Didymium difforme (Pers.) Duby

Bot. GaU. 2 : 858. 1830.
PL VIII, Figs. 172, 173.

1797. Diderma difforme Pers., Tent. Disp. Meth. 19.

1803. Licea ccesia Schum., Enum. PL Saell. 2 : 219.

1809. Physarum difforme Lk., Mag. Ges. Nat. Fr. Bed. 3 : 27.

1813. Amphisporium versicolor Link, Mag. Ges. Nat. Fr. Berl. 7 : 41.

1817. Didymium cyanescens Fr., Symb. Gast. 19.

1823. Licea alba Nees, in Kunze & Schmidt Myc. 2 : 66.

1823. Lycogala minutum Grev., Scot. Crypt. Fl. 40.

1825. Reticularia pusilla Fr., Syst. Orb. Veg. 1 : 147.

1829. Diderma cyanescens Fr., Syst. Myc. 3 : 109.

1829. Physarum album Fr., Syst. Myc. 3 : 147.

DIDYMIUM 119

1829. Physarum ccesium Fr., Syst. Myc. 3 : 147.

1832. Licea macrospora Schw., Trans. Am. Phil. Soc. II. 4 : 258.

1836. Diderma nitens Klotzsch, in Sm., Engl. Fl. 5 (2) : 311.

1837. Diderma neesii Corda, Icon. 2 : 23.

1849. Leocarpus cyanescens Fr., Summ. Veg. Scand. 450.

1850. Diderma libertianum Fres., Beitr. Myc. 28.

1864. Didymium libertianum (Fres.) de Bary, Mycetozoen 124.

1873. Chondrioderma difforme (Pers.) Rost. in Fuckel, Symb. Myc. Nachtr. 73.

1876. Chondrioderma liceoides Rost., Mon. App. 17.

1899. Diderma persoonii Macbr., N. A. Slime-Moulds 96.

1919. Didymium tubulatum Jahn, Ber. Deutsch. Bot. Ges. 36 : 663.

Plasmodiocarpous, the smooth, white outer peridium separable
from the thin, colorless or purplish inner layer; capillitium of rather
coarse, flat, dichotomously branching threads, broader below; spores
minutely warted or almost smooth, dark brown, 12-14 /x.

The white crust-like outer wall has more than once carried this
species into Diderma. It is doubtful whether or not Chondrioderma
calcareum Rost. should be referred here. Miss Lister cites a variety,
comatum, with finer and more abundant capillitium, which may repre-
sent Rostafinski's species. The spores seem to be paler and somewhat
smaller. In some of our specimens the crust-like outer peridium shows
crystals on the broken edge only. The var. repandum G. Lister (D. tubu-
latum Jahn) is characterized by tubular or funnel-shaped ingrowths
reaching from the upper part of the peridium to the base. It may
prove to be distinct.

Reported common on Long Island by Mr. Hagelstein and in Oregon
by Mr. H. C. Gilbert, rare elsewhere in the United States, also re-
ported from Bolivia; not uncommon in the old world.

21. Didymium quitense (Pat.) Ton.

Fl. Myx. 150. 1909.
PI. VIII, Fig. 174.

1895. Chondrioderma quitense Pat., Bull. Soc. Myc. Fr. 11 : 212.

Sporangia more or less plasmodiocarpous, scattered, depressed,
white; the outer peridium distinct, crust-like, remote from the thin
membranous inner wall; columella undefined; capillitium brown, much
branched, forming a network, especially outwardly; spores very dark
violaceous brown, rough with a tendency to obscure reticulation,
12-15 n or larger, up to 17 \x.

This species is different from D. difforme chiefly in the rougher and
somewhat banded epispore. The collection with large spores, 15-17 n,
is somewhat doubtfully here referred.

Colorado, Montana, California, Ecuador.

120 THE MYXOMYCETES

22. Didymium trachysporum G. Lister

Essex Naturalist 20 : 113. 1922.

Sporangia more or less scattered, white or cream white, either
hemispherical, 0.2-0.6 mm. in diameter, or forming slender, curved,
simple or ring-shaped plasmodiocarps; the outer wall a smooth or
wrinkled crust of closely compacted lime granules; the inner wall
membranous, colorless; the floor of sporangium pale yellow, mem-
branous, with a thickened margin, with scanty, rarely abundant de-
posits of lime crystals; capillitium rather scanty, variable, consisting
usually of a network of colorless or purplish, stout or slender threads,
sometimes with vesicular expansions enclosing lime crystals; spores
brownish purple, marked with short spines which are scattered or
grouped in clusters, rarely with patches of broken reticulation, the
spore wall often traversed by a low ridge, 9-10 /x. Plasmodium colorless.

Oregon; Europe.

3. Physarina von Eohnel

Sitzungsb. K. Akad. Wiss. Wien, Math.-Nat. Kl. 118 (1) : 431. 1909.

Sporangia rough with numerous blunt, cylindrical, peg-like processes
projecting from the surface; capillitium without nodes.
One species.

Physarina echinocephala von Hohnel

Sitzungsb. K. Akad. Wiss. Wien, Math.-Nat. Kl. 118 (1) : 432. 1909.

PL XXI, Fig. 573.

Sporangia gregarious, stalked, subglobose, 0.4-0.5 mm. in diameter,
pale pink or flesh colored in herbarium, blackish brown when gathered;
outer layer of sporangium somewhat cartilaginous, bearing numerous
cylindrical processes filled with lime; inner wall smooth, membranous;
stalk stout, tapering, furrowed, flesh colored to nearly white, filled
with lime, continued above into a pale subglobose columella; capillitium
violet-brown, paler and branching at tips; spores nearly smooth,
brownish violet, 7-9 fi.

Java.

4. Diderma Persoon
Roem. N. Mag. Bot. 1 : 89. 1794.
1873. Chondrioderma Rost., Versuch 13.

Sporangia plasmodiocarpous or distinct, sessile or stipitate; peridium
as a rule double, the outer wall generally calcareous with the lime gran-
ules globular, non-crystalline, the inner wall very delicate and often,

DIDERMA 121

in the mature fructification, remote from the outer; columella generally
prominent.

The genus Diderma is usually easy of recognition, by reason of its
double wall, the outer crustaceous and usually calcareous, and its
limits remain substantially as originally set by Persoon. His definition
is as follows:

"Peridium ut plurimum duplex; exterius fragile; interius pellucens,
subdistans. Columella magna, subrotunda. Fila parca latentia."
(Syn. Meth. Fung. 164.)

Rostafinski changed the name of the genus to Chondrioderma,
seemingly at de Bary's suggestion, and seems to have regarded Per-
soon's definition as applicable to those species in which the wall is not
only plainly double, but in which the two walls are as plainly remote
from each other. More especially he esteemed a new generic name
necessary, since he regarded several included species, e. g., D. spumari-
oides, D. hemisphericum, as monodermic. Persoon's Diderma, when
established, included D. floriforme. He caused some confusion in his
later work by admitting certain physarums. This induced Schrader
to throw all the didermas into his new genus, Didymium.

KEY TO THE SPECIES OF DIDERMA

Outer wall of sporangium calcareous, crustose, fragile;

inner wall membranous, usually distant, rarely lacking I. Section Eudiderma
Outer wall of sporangium cartilaginous; inner wall often

not distinct, or concrete with the outer II. Section Leangium

I. EUDDDERMA

o. More or less plasmodiocarpous or on a plasmodiocarp-

like hypothallus °

a. Sporangiate or forming small separate plasmodiocarps d

b. Broadly effused, flattened, varying to short plasmo-
diocarps massed in a larger network; occasionally of
separate sporangia; spores 7-10 \x I. D. ejfusum

b. Plasmodiocarps smaller, spores larger c

c. Plasmodiocarpous, or sporangiate on a plasmodiocarp-

like hypothallus; spores about 12 n 2. D. alpinum

c. Plasmodiocarpous to discoid, rarely with a short stalk;

spores 10-15 yn 3. D. chondrioderma

d. Spores marked with prominent but incomplete

reticulations 4. D. subdictyospermum

d. Spores warted, spiny or nearly smooth e

e. Brown or brick-red, fading to brownish ochraceous. . 5. D. simplex

e. White, grayish or pale flesh colored /

/. Seated on a common hypothallus i

f. Sporangia not on a common hypothallus *

g. Outer wall not porcelain-like, adhering to inner wall . . 6. D. spumarioides

122 THE MYXOMYCETES

g. Outer wall firm, porcelain-like, separate from the

inner wall h

h. Sporangia in a dense, crustose mass; walls remote;

spores 1 1-14 \i 7. D. crustaceum

h. Sporangia gregarious; walls remote; spores 7.5-10 ju 8. D. globosum
h. Sporangia crowded, large, substipitate, walls close;

inner wall and columella brownish or flesh colored 9. D. lyallii

i. Sporangia sessile j

i. Sporangia stipitate k

j. Outer peridium white or pallid; inner distinct,

ochraceous; capillitium duplex 10. D. niveum

j. Outer wall porcelain- like, pale rose; capillitium

simple 11. D. testaceum

k. Sporangia greatly flattened, discoid 12. D. hemisphcericum

k. Sporangia hemispherical to subglobose 13. D. montanum

II. Leangium

a. Sessile, rarely short-stipitate b

a. Usually with a distinct stipe /

b. Inner peridium distinct c

b. Peridial layers more or less united d

c. Brownish or pinkish gray; spores 12-13 fx 14. D. sauteri

c. Ochraceous or olivaceous; spores 9-11 /jl 15. D. ochraceum

c. White above, deep red below; columella clavate,

rough, deep red 16. D. car-rubrum

d. Middle layer of peridium subcrystalline; columella

usually lacking 17. D. trevelyani

d. Middle layer of peridium not crystalline e

e. Peridium chocolate, marked before dehiscence with

lines converging at apex; columella white 18. D. aster oides

e. Pinkish or red-brown; columella cream colored, rough 19. D. antarcticum
e. Dark gray to nearly black; columella lacking 20. D. imperiale

j. Stipe short, less than height of sporangium g

f. Stipe equal to or exceeding height of sporangium h

g. Ashy to brownish drab 21. D. radiatum

g. Umber to red-brown 22. D. roanense

g. Orange-red or vermilion 23. D. lucidum

h. Brownish gray, ochraceous brown or umber; wall

smooth; dehiscence revolute 24. D. floriforme

h. White or grayish; wall rugulose, areolate and

areolately dehiscent 25. D. rugosum

1. Diderma effusum (Schw.) Morgan

Jour. Cin. Soc. Nat. Hist. 16 : 155. 1894.
PI. VIII, Figs. 178, 179, 180, 181.

1832. Physarum effusum Schw., Trans. Am. Phil. Soc. II. 4 : 257.
1898. Physarum crustijorme Speg., An. Mus. Nac. Buenos Aires 6 : 200.

Fructification composed of flattened white sporangia massed in
plasmodiocarpous fashion, applanate, reticulate, or often forming a

DIDERMA 123

broadly effused mass; outer peridium a thin, white, calcareous crust
closely applied to the delicate membranous and colorless inner wall;
columella thin, alutaceous, scarcely more than a base of the plasmodio-
carp; capillitium pale, consisting of short threads somewhat branched
toward their distal extremities; spores faintly echinulate, with a few
clusters of darker and larger, but still minute spines, 7-9 li.

The two layers of the peridium are sometimes scarcely distinguish-
able, the outer a thin, crustose shell closely applied to the membranous
inner wall.

New York, Ohio, Nebraska, Argentina; apparently rare in America.
Widespread in the old world and said to be not infrequent in the
British Isles. Africa, East Indies, Japan.

Var. reticulatum (Rost.) Macbride, N. A. Slime-Moulds ed. 2. 131,
1922 (= Didymium reticulatum Rost., in Fuckel, Symb. Myc. Nachtr.
73, 1873; Chondrioderma reticulatum Rost., Mon. 170, 1875; Diderma
reticulatum (Rost.) Morg., Jour. Cin. Soc. Nat. Hist. 16 : 155, 1894).
Sporangia gregarious, generally rounded, not much depressed, flat,
sometimes, especially toward the margin of a colony, elongate, venu-
lose or somewhat plasmodiocarpous, dull white, the inner peridium
ashen or bluish, remote from the calcareous crust, which is extremely
fragile, easily shelling off; columella indistinguishable from the base
of the sporangium, thin, alutaceous; capillitium of short, generally
colorless, delicate, sparingly branching or anastomosing threads per-
pendicular to the columella; spores black in mass, by transmitted
light violet-tinted, nearly smooth, with a few shadows marking clusters
of minute spines, 7-9 ix.

Perhaps our most common form. Found in fall on dead twigs,
leaves, etc. Recognized by its rather large, white, depressed or flat-
tened sporangia tending to form reticulations, and hence suggesting
the name. The lines of fruiting tend to follow the venation of the
supporting leaf; where the sporangium is round, the columella is a
distinct rounded or cake-like body; where the fruit is venulose, the
columella is less distinct.

New York, Pennsylvania, Ohio, Wisconsin, Iowa, Nebraska, probably
throughout the eastern United States, Brazil; Europe, Ceylon, Java.

2. Diderma alpinum Meylan

Bull. Soc. Vaud. Sc. Nat. 51 : 261. 1917.

1913. Diderma globosum Pers. var. alpinum Meylan. Ann. Cons. Bot. Geneve

310.
Plasmodiocarpous or sporangiate, the plasmodiocarps short, the
sporangia sessile and crowded on a plasmodiocarp-like hypothallus,

124 THE MYXOMYCETES

0.7-1 mm. broad; outer layer smooth, shell-like, inner membranous,
gray or somewhat iridescent; columella convex, rough, ochraceous to
flesh colored; capillitium rather stout, of straight to flexuose, branch-
ing threads, pale to purplish, with numerous dark, fusiform thicken-
ings; spores dark purple, rather roughly warted, 11.5-12.3 ju.

Miss Lister says the inner wall is flesh colored. This is not the case
in our specimens, received from M. Meylan. The spores also average
12.3 ix, somewhat larger than as described.

Switzerland, abundant in the mountains, Hungary.

3. DlDERMA CHONDRIODERMA {de B. & Rost.) G. List.

Mycetozoa ed. 3. 258. 1925.
PI. XXI, Figs. 566, 567, 568, 569.

1872. Didymium chondrioderma de B. & Rost., in Alex. Stroj. 89.

1875. Chondrioderma alexandrowiczii Rost., Mon. 169.

1913. Diderma arboreum G. List. & Petch, Jour. Bot. 51 : 2. 1913.

Sporangia scattered, discoid, sessile or rarely stalked, 0.5-0.7 mm.
in diameter, or forming expanded and lobed, flattened plasmodiocarps
1-3 mm. in diameter, white or purplish gray from lack of lime; spo-
rangium wall membranous with deposits of round or angular lime
granules either united to form a thin crust or sparsely distributed,
often with scattered deposits of refuse matter; stalk, when present, very
short, dark brown; columella flesh colored, sometimes nearly obsolete;
capillitium rather coarse, purplish or colorless, often with membranous
expansions at the joints; spores very minutely and closely spinulose,
pale purplish gray, 10-15 /jl. Plasmodium white, then violet.

Distinguished from D. effusum by the larger spores and coarser
capillitium.

Iowa; Europe, Ceylon, Malay Peninsula, Japan.

4. Diderma subdictyospermum (Rost.) Lister

Mycetozoa ed. 2. 101. 1911.

1876. Chondrioderma subdictyospermum Rost., Mon. App. 16.
1892. Chondrioderma dealbatum Mass., Mon. 207.

Sporangia crowded, sessile on a white hypothallus, subglobose or
hemispherical, 0.3-0.5 mm. in diameter, white; outer sporangium wall
thick, fragile, crustose, closely adhering to the membranous inner
layer; columella hemispherical or subglobose, white; capillitium dark
purplish, rigid, sparingly branched; spores purplish brown, marked
with prominent raised ridges or broken reticulations, about 12 ju.

The type in the British Museum is labelled Didymium dealbatum

DIDERMA 125

Berk. & Curt., and the species was distributed under that name in
Fendler, Venezuela Fungi, but the name was never published.
Venezuela; Hungary, South Africa, Ceylon, Java.

5. Diderma simplex {Schroet) List.

Mycetozoa ed. 2. 107.
PL VIII, Figs. 182, 183.

1885. Chondrioderma simplex Schroet., in Cohn, Krypt.-Fl. Schles. 3 (1) : 123.

Sporangia gregarious, sessile, globose or depressed-globose, 0.3-0.5
mm. in diameter, or sometimes plasmodiocarpous; brown or brick-red
when fresh, fading to ochraceous with age; hypothallus everywhere in
evidence; columella ill-defined; capillitium scanty, the threads delicate,
pale, branching as they join the peridial wall; spores dull violaceous,
slightly roughened, 8-10 /*. Plasmodium yellow-brown.

A rather crude, primitive representative of this beautiful genus. The
inner peridium seems to be lacking — a comfort to Rostafmski ! Rare.
Our best specimens are from New Jersey, by courtesy of Dr. C. L.
Shear. These went to fruit on leaves and branches of Vaccinium. It
seems to affect the heather of Europe, moorland, etc. We have also
specimens from the herbarium of Mr. Bilgram. In no American gather-
ing examined does the capillitium show calcareous thickenings as
described by the British text. Meylan suggests that the American
forms are specifically distinct from those of Europe.

The var. echinulatum Meylan is described as having bright yellow
sporangium and columella and more spinulose spores.

Rare in North America— New Hampshire, New Jersey, Pennsyl-
vania, North Carolina, Chile; Europe.

6. Diderma spumarioldes Fries

Syst. Myc. 3 : 104. 1829.
PI. VIII, Figs. 184, 185.

1818. Didymium spumarioldes Fr., Symb. Gast. 20.

1833. Physarum stromateum Link, Handb. 3 : 409.

1849. Carcerina spumarioldes Fr., Summ. Veg. Scand. 451.

1875. Chondrioderma spumarioldes (Fr.) Rost., Mon. 174.

1876. Chondrioderma stromateum (Lk.) Rost., Mon. App. 18.
1892. Chondrioderma virgineum Massee, Mon. 207.

1894. Diderma stromateum (Lk.) Morgan, Jour. Cin. Soc. Nat. Hist.

16 : 152.
1894. Diderma clnereum Morgan, Jour. Cin. Soc. Nat. Hist. 16 : 154.

126 THE MYXOMYCETES

Sporangia sessile, white, crowded, spherical or by mutual pressure
irregular; peridium plainly double, but the layers adhering, the outer
more strongly calcareous, but very frail, almost farinaceous; hypo-
thallus more or less plainly in evidence, white or pale alutaceous;
columella distinct, though often small, globose, white or yellowish;
capillitium variable in quantity, sometimes abundant, brown, some-
what branching and anastomosing outwardly, the tips paler; spores
distinctly but rather sparsely warted, dark violaceous, 8-11 ix.

This species has the outward seeming of a didymium, but is plainly
different as that genus is here defined, since the calcareous crust, al-
though inclined to be pulverulent, is made up of minute granules, not
crystals, of lime. The hypothallus is sometimes hardly discoverable,
sometimes well developed, rugulose, extending far beyond the limits of
the fructification. In the Monograph, p. 175, Rostafmski includes here
Physarum stromateum Link. In the Appendix he is inclined to raise
Link's form to the dignity of a distinct species, basing the diagnosis
upon the superposition of the sporangia in certain cases, a feature en-
tirely unknown to Link's description and of extremely uncertain value,
since by their crowding the sporangia are likely always to be pushed
above each other. We therefore regard Chondrioderma stromateum
(Link) Rost. as a synonym of the present species, as the original
description, so far as it goes, indicates.

Forms in which the hypothallus is lacking or poorly developed were
formerly placed in D. cinereum Morgan, but there is a perfect transi-
tion between such forms and the typical phase.

Widely distributed in North America and Europe. Also reported
from Bolivia, Chile; Ceylon, Java, Manchuria, Japan.

7. DlDERMA CRUSTACEUM Peck

Rept. N. Y. State Museum 26 : 74. 1874.
PI. IX, Figs. 186, 187.

1888. Chondrioderma crustaceum (Pk.) Berlese, in Sacc, Syll. Fung. 7 : 373.
1899. Chondrioderma globosum (Pers.) Rost. ex Lister, Mycetozoa 78, in part.
1911. Diderma globosum Pers. ex List., Mycetozoa ed. 2. 104, in part.

Sporangia closely crowded or superimposed, in a cushion-like colony,
creamy white or occasionally pinkish, globose, embedded in the sub-
stance of the hypothallus, the outer peridium smooth, delicate, crus-
taceous, fragile, remote from the blue iridescent inner membrane;
hypothallus prominent; columella variable, generally present, globose;
capillitium dark colored, the threads branching and combining to
form a loose net; spore-mass black; spores by transmitted light dark

DIDERMA 127

violaceous, distinctly warted, 12-15 fx. Plasmodium at first watery,
colorless, becoming at length milky white.

The didermas are generally delicately beautiful. The outer wall in
the present species is like finest unglazed china, softly smooth, and yet
not polished, often absolutely white, with porcellanous fracture. An
interparietal space separates the outer from the inner wall, so that the
former may be broken, bit by bit, without in the least disturbing the
underlying structure. The inner wall is ashen or gauzy iridescent-green,
sending back all colors in reflected light. The spores are violet, deeply
so when fresh, the capillitium strong and likewise tinted ; the columella
passing down and blending with the common snow-white hypothalline
base. In the Lister monograph included with D. globosum but the
two species are distinctly different in habit. In the one the distinct
sporangia are associated but not crowded; in the other all are massed
together, forming chalky masses of considerable size, 2 or 3 cm., over-
crowded, superimposed, where the sporangia are irregular in shape and
size by reason of mutual pressure. The plasmodium develops in forests
and orchards, among decaying leaves, but is inclined to rise as maturity
draws near, to ascend some erect twig, or the stem of a living plant to
the height of several inches where the sporangia at length appear
"heaped and pent," an encircling sheath, conspicuous after the fashion
of Mucilago, for which it is indeed sometimes mistaken.

Common. Distinguished from the following species by the larger
and more distinctly marked spores and the more crowded habit.
New England and Ontario west to Nebraska; Europe.

The species reported from Manchuria by Skvortzow (1931), as
D. globosum, is said to have spores 1 1-1 1.5 n. It is probably this species.

8. DlDERMA GLOBOSUM PerS.

Roemer N. Mag. Bot. 1 : 89. 1794.
PL IX, Figs. 188, 189.

1804. Reticularia globosa (Pers.) Poiret, in Lam. Encycl. 6 : 182.

1827. Cionium globosum (Pers.) Spreng., Syst. Orb. Veg. 4 : 529.

1875. Chondrioderma globosum (Pers.) Rost., Mon. 180.

1876. Chondrioderma off ine Rost., Mon. App. 18.
1876. Chondrioderma similans Rost., Mon. App. 20.

Sporangia more or less closely gregarious, sessile, globose or by mu-
tual pressure prismatic or polyhedral, white, the outer wall smooth,
polished, crustaceous, fragile, far remote from the inner, which is
thin, smooth or rugulose, iridescent-blue; hypothallus usually pro-
nounced and spreading beyond the sporangia, sometimes scanty or

128 THE MYXOMYCETES

lacking; columella white, variable, sometimes very small, inconspicu-
ous, sometimes large, globose, ellipsoidal, even pedicellate; capillitium
abundant, brown or purplish brown, branching and occasionally
anastomosing to form a loosely constructed superficial net; spores
globose, delicately spinulose, 7.5-10/*.

As noted under D. crustaceum, Lister includes that species in the
present one and gives the spore measurements as 10-14 /i, rather a
wide range. But Rostafinski said 8.3 /*, the fraction indicating caution,
as though it were the average of several measurements. We do have
the small-spored form, although it is rare, and it may be what Rosta-
finski had in mind. In some of our material the spores attain 10 n and
the measurements are changed in accordance with this conception of
the species.

Rare. Ohio, Wisconsin, Iowa, Washington; Hungary, Rumania,

North Africa.

9. Diderma lyallii (Massee) Macbr.

N. A. Slime-Moulds 99. 1899.
PI. IX, Figs. 190, 191.

1892. Chondrioderma lyallii Massee, Mon. 201.

1911. Diderma niveutn (Rost.) Macbr. var. lyallii Lister, Mycetozoa ed. 2. 105.

Sporangia obovate, more or less closely crowded, white, creamy or
pallid carneous, substipitate, about 1 mm. in diameter; outer peridium
firm, stout, encrusted, especially above, with granular masses of lime,
the inner well developed, close to the outer, more or less cartilaginous,
opaque, yellow or buff colored; hypothallus well developed, venulose,
white, passing up unchanged to form the short, stout stipe and lower
outer peridium; columella prominent, half the height of the sporan-
gium, flesh colored or brown; capillitium of short, brown threads, rigid,
much branched, forming a net, widened irregularly and especially at
the nodes; spore-mass black; spores by transmitted light dark brown,
rough, 14-17/1.

A very distinct species, the large, fine, showy sporangia in more or
less crowded clusters springing from a snow-white, common hypo-
thallus. First reported from western Canada, it has since been found
throughout the region from the Rocky Mountains to the Pacific.
Meylan believes it should be grouped with the leangiums. Occasionally
the outer peridium is broken up into calcareous plates, as in Lepido-
derma. Specimens from Rumania, distributed by Brandza, No. 97,
show an extreme development of this tendency.

Western United States and Canada, Chile; Europe.

DIDERMA 129

10. Diderma niveum (Rost.) Macbr.

N. A. Slime-Moulds 100. 1899.
PI. IX, Figs. 192, 193.

1829. Diderma deplanatum Fr., Syst. Myc. 3 : 110.

1849. Leocarpus deplanatus Fr., Summ. Veg. Scand. 450.

1875. Chondrioderma niveum Rost., Mon. 170.

1875. Chondrioderma physaroides Rost., Mon. 170.

1876. Chondrioderma deplanatum (Fr.) Rost., Mon. App. 17.

1877. Diderma albescens Phill., Grev. 5 : 114.

1892. Chondrioderma albescens (Phill.) Massee, Mon. 209.

Sporangia gregarious, scattered, or more often crowded, sessile,
depressed-spherical, sometimes ellipsoidal or elongate, white, the
outer peridium crustaceous, chalky, smooth and fragile, the inner dis-
tinct, delicate, ochraceous; hypothallus scant or none; columella well
developed, globose or hemispherical, orange-tinted or ochraceous; cap-
illitium abundant, made of threads of two sorts, some purplish or
dusky, with pale extremities, uneven, others more delicate and color-
less, and with wart-like thickenings, all sparingly branched; spores
violet-brown, minutely roughened, 9-13 /x.

This species is not common. From Colorado we have fine specimens
typical in every way. Specimens from Washington are flatter, and may
represent D. deplanatum Fr. In the Mycetozoa ed. 3. 90, Miss Lister
treats this as a distinct species, distinguishing it from D. niveum by its
plasmodiocarpous habit and absence of columella. But in the descrip-
tion it is stated "Columella hardly developed or broadly convex,
orange" which seems to leave the distinction uncertain, to say the
least. Furthermore, in the American collections there is no correlation
between the small spores and the flattened columella, the latter being
rather associated merely with the plasmodiocarpous phase. This is
less true of the European collections at hand, but most of them are
obviously incomplete developments, with many giant and imperfectly
matured spores. If the two species are finally proved to be identical,
Fries' name must take precedence. Pending such final proof, we retain
the more familiar name.

Colorado, Washington, Oregon, California; Europe.

Diderma microcarpum Meylan (Bull. Soc. Vaud. Sc. Nat. 55 : 240,
1924) is certainly very close to the preceding species, although the
author regards it as distinct. The sporangia are smaller, 0.3-1 mm. in
diameter, the peridial layers rarely separated, the spores 10-1 1 /x.

130 THE MYXOMYCETES

11. Diderma testaceum {Schrad) Pers.

Syn. Meth. Fung. 167. 1801.
PI. IX, Figs. 194, 195.

1797. Didymium testaceum Schrad., Nov. Gen. Plant. 25.

1827. Cionium testaceum Spreng., Syst. Orb. Veg. 4 : 529.

1869. Diderma cubense Berk. & Curt., Jour. Linn. Soc. 10 : 347.

1873. Chondrioderma testaceum (Schrad.) Rost., Vers. 13.

1873. Diderma sublateritium Berk. & Br., Jour. Linn. Soc. 14 : 82.

1874. Diderma marice-wilsoni Clinton, Rept. N. Y. State Mus. 26 : 74.
1876. Chondrioderma sublateritium (Berk. & Br.) Rost., Mon. App. 19.
1876. Chondrioderma cubense (Berk. & Curt.) Rost., Mon. App. 19.

Sporangia gregarious, sessile, depressed-spherical or sometimes elon-
gate, small, 1 mm. or less, rose-white, smooth, the outer peridium
crustaceous, rather thick and persistent, polished, slightly raised above
the inner, which is dull ashen and more or less wrinkled; hypothallus
none; columella prominent, hemispherical in the typical rounded forms,
slightly rough, reddish or reddish alutaceous; capillitium usually
abundant, of slender, delicate, pale or colorless threads, little branched,
smooth; spores violaceous brown, minutely roughened, 8-9 /x.

Easily recognized when fresh by its delicate pink or roseate color;
weathered specimens tend to become white, and might be confused
with forms of D. effusum, but the sporangia in the present species
are less flattened and only rarely and in special situations exhibit the
linear or plasmodiocarpous shapes characteristic of D. reticulatum.
All our specimens from the west are on dead leaves of oak; eastern
gatherings are on moss, beech, maple and aspen leaves and occasionally
on woody debris.

Not common but widely distributed — New England to Washington,
California, South Carolina; Europe, North Africa, Japan, Ceylon.

12. Diderma hemisphcericum {Bull) Hornem.

Fl. Dan. 33 : 13. 1829.
PL IX, Figs. 196, 197.

1791. Reticularia hemisphcerica Bull., Champ. 93.

1803. Physarum depressum Schum., Enum. PI. Saell. 2 : 202.

1804. Reticularia contorta Poiret, in Lam. Encycl. 6 : 182.
1829. Didymium hemisphcericum (Bull.) Fr., Syst. Myc. 3 : 115.
1832. Didymium michelii Lib., PI. Ard. fasc. II, 180.

1842. Physarum michelii (Lib.) Corda, Icon. Fung. 5 : 57.

1873. Chondrioderma michelii (Lib.) Rost., in Fuckel, Symb. Myc. Nachtr. 74.

1894. Diderma michelii (Lib.) Morg. Jour. Cin. Soc. Nat. Hist. 16 : 153.

1909. Chondrioderma hemisphcericum (Bull.) Torrend, Fl. Myx. 163.

Sporangia gregarious, orbicular, discoid, depressed above and often
umbilicate below, stipitate or sometimes sessile, the outer peridium

DIDERMA 131

white, fragile, crustaceous, soon breaking about the margins, closely-
applied to the inner, which is delicate, cinereous and ruptures irreg-
ularly; stipe about equal to the diameter of the sporangium, 1 mm.,
rather stout, calcareous, nearly white or pallid to brownish or aluta-
ceous, more or less wrinkled longitudinally, the wrinkles, when present,
forming veins on the lower surface of the sporangium; hypothallus
small; columella not distinct from the thickened brownish or reddish
base of the sporangium; capillitium of delicate threads, mostly simple
and colorless, often scanty; spores pale violaceous, nearly smooth,
8-9 ix. Plasmodium opaque white.

A very well-marked species, easily recognized, at least when stip-
itate, by its remarkable discoid or lenticular sporangia. The name
hemis pharicum is unsuitable, as the sporangia are not hemispherical.
After the spore dispersal, the stipes are long-persistent, surmounted
by a peculiar disk representing the consolidated columella, lower
sporangial wall, and expanded stem-top. Sessile specimens are like
similar forms of D. reticulatum, but in all the gatherings before
us the stipitate type is at hand to reveal the identity of the
species.

Rostafinski's figs. 131, 146, 149, and 150, adapted from Corda,
exaggerate the hypothallus, but otherwise leave nothing to be desired.

As to synonymy, Bulliard has plainly the priority. His figure,
pi. 446, fig. 1, can refer to nothing else, especially reenforced as it is
by Sowerby, Eng. Fung. PI. 12.

Rather rare on fallen stems of herbaceous plants, but widely dis-
tributed, New England to Oregon and Washington, Puerto Rico,
Argentina; Europe, South Africa, Ceylon, Java, Japan.

13. Diderma montanum Meylan

Bull. Soc. Vaud. Sc. Nat. 53 : 454. 1921.
PL IX, Figs. 198, 199.

1910. Chondrioderma montanum Meyl., Bull. Soc. Bot. Geneve 2 : 262.

Sporangia scattered or in groups, subglobose, stalked, flattened or
umbilicate beneath, pearl or pinkish gray or nearly white, smooth or
somewhat wrinkled, 0.6-0.8 mm. in diameter; sporangium wall of two
often separating layers, the outer densely charged with lime granules,
the inner reddish brown throughout or towards the base; stalk pale
or bright brownish yellow, slender or stout, enclosing white lime de-
posits, 0.1-0.8 mm. high; columella small, globose or hemispherical,
brownish red, sometimes stalked; capillitium of slender purplish or

132 THE MYXOMYCETES

hyaline threads, branched and anastomosing toward the extremities;
spores pale brownish purple, faintly spinulose, 8-10 ix.

New York, Colorado; Europe.

Var. album G. Lister (= Chondrioderma radiatum var. album Tor-
rend), with white or bluish white sporangia and white or creamy
columellae, and var. roseum Meylan, with pale pink sporangia and
stalks and dull pink columellae, occur locally in Europe.

14. Diderma sauteri {Rost) Macbr.

N. A. Slime-Moulds 103. 1899.

1875. Chondrioderma sauteri Rost., Mon. 181.

1891. Chondrioderma aculeatum Rex, Proc. Acad. Nat. Sc. Phila. 390.

Sporangia scattered, gregarious, sessile, lenticular or hemispherical,
flattened above and sometimes concave or umbilicate below, pale
brownish or pinkish gray or dull ochraceous, the outer peridium
papyraceous, thin, occasionally wrinkled, rupturing irregularly, re-
mote from the inner, which is thin, delicate, semi-transparent, grayish,
rarely iridescent; hypothallus none; columella irregular, sometimes
small and hardly evident, rugose, with spine-like processes, the per-
sisting bases of the capillitial threads reddish brown ; capillitium scanty,
white or colorless, simple or sparingly branched; spores dark violaceous,
spinulose, 12-13 fi.

After careful comparison of specimens and various descriptions,
especially that of Rostafinski, with the type specimens of Rex, we
concur with Lister in adopting Rostafinski's name. The sporangia in
Rex's type specimens are on moss, borne at the extreme tips of acu-
minate or aculeate leaves, so that at first sight they appear stipitate.

Apparently rare. Maine, New York; Europe.

15. Diderma ochraceum Hojfm.

Deutsch. EL Crypt. PI. 9, Fig. 2 b. 1795.

1804. Reticularia ochracea (Hoffm.) Poir., Lam. Encycl. 6 : 182.

1885. Chondrioderma ochraceum Schroet, Cohn Krypt. Fl. Schles. 3 (1) : 124.

Sporangia gregarious or clustered, 0.7-1 mm., sessile, globose or some-
times plasmodiocarpous, ochraceous or olivaceous, yellow; outer wall
cartilaginous with yellow deposits of lime, the inner also yellow, adher-
ent or free; columella not distinct; capillitium simple or branching,
purple-brown, hyaline at base; spores spinulose, purplish gray, 9-11 p.

Brandza states that when the sporangia mature under dry condi-
tions the wall is single and the fructifications resemble sessile forms of
Lepidoderma tigrinum.

Reported from Massachusetts; also Europe, Japan.

DIDERMA 133

16. DlDERMA COR-RUBRUM Macbr.

N. A. Slime-Moulds ed. 2. 140. 1922.
1925. Diderma montanum Meylan ex Lister, Mycetozoa ed. 3. 83, in part.

Sporangia gregarious, clustered, small, 0.5-0.7 mm., sessile,
corrugate-plicate, especially above, snow-white, the outer peridium
cartilaginous, polished without and within, the inner delicate, evanes-
cent; columella well developed, globose or clavate, anchored by several
stout transverse trabecular to the peridial wall, papillate, deep red as
is the peridium, especially below; capillitium very delicate, sparingly
branching, colorless; spores verruculose, fuliginous, tinged with red,
about 12 /x.

This curious but elegant little species is represented by a single
colony collected by Professor Morton Peck on rotten wood in Iowa.
It resembles D. sauteri but is distinguished by the plicate white wall,
the stout columella with its lateral extensions, as by the more delicate
spores. Miss Lister includes it in D. montanum, from which the de-
scription would seem to exclude it. The type and only collection is
in the British Museum, but it is to be hoped that it will appear again
in the original locality.

Iowa.

17. Diderma trevelyani {Grev.) Fr.

Syst. Myc. 3 : 105. 1829.
PL IX, Figs. 200, 201.

1825. Leangium trevelyani Grev., Scot. Crypt. Fl. 132.

1842. Polyschismium trevelyani (Grev.) Corda, Icon. Fung. 5 : 20.

1875. Chondrioderma trevelyani (Grev.) Rost., Mon. 182.

1875. Chondrioderma cerstedtii Rost., Mon. 184.

1877. Diderma geasterodes Phill., Grev. 5 : 113.

1877. Diderma laciniatum Phill., Grev. 5 : 113.

1892. Chondrioderma geasteroides (Phill.) Massee, Mon. 201.

Sporangia scattered, globose or nearly so, smooth or verruculose,
yellow-brown, reddish brown or rufescent, sessile or short-stipitate;
peridium firm, splitting more or less regularly into unequal, revolute,
petal-like lobes which are white within, composed of three layers, a
thin cartilaginous outer layer and a membranous inner layer, con-
nected by a thick calcareous middle layer composed of coarse, some-
what crystalline lime clusters, the outer layer often splitting to form
plates suggesting Lepidoderma; stipe, when present, equal, furrowed,
concolorous; columella small or none; capillitium abundant, the threads
rather rigid, purple or purplish brown, branching and anastomosing,
more or less beaded; spores dark, violaceous brown, spinulose, 11-14 ix.

134 THE MYXOMYCETES

In 1876, Harkness and Moore collected in the Sierra Nevada Moun-
tains of California forms of Diderma which are described by Phillips
(Grev. 5 : 113) as D. geasterodes and D. laciniatum. English author-
ities who have examined the material agree that the forms described
constitute but a single species, and Lister makes them identical with
D. trevelyani (Grev.) Fr. Rostafinski's figs. 161, 162, are evidently
reproduced from Fries. Nees von Esenbeck's pi. IX, fig. 4, also repre-
sents this species. Massee describes a columella; Lister says there is
none. As a matter of fact, the same cluster of sporangia may show
some with a columella and some without. In a collection of Morgan's
from Ohio, labelled Lepidoderma geaster Link, which seems to belong
here, the columellas are uniformly well developed.

The variety nivale Meylan (Bull. Soc. Vaud. 50 : 189, 1914) is a
large, mottled, rugose, often plasmodiocarpous form, occurring in the
Swiss Alps.

Ohio, Colorado, Washington, Oregon, California, Argentina, Chile;
Europe.

18. Diderma asteroides Lister

Mycetozoa ed. 2. 113. 1911.
PI. IX, Figs. 202, 203.

1902. Chondrioderma asteroides List., Jour. Bot. 40 : 209.

Sporangia globose or ovoid-globose, the apex more or less acuminate,
sessile, sometimes narrowed at the base to a short, thick stalk, brown-
or chocolate-tinted, marked at the apex by radiant lines, and at length
dehiscent by many reflexing lobes revealing the snow-white adherent
middle peridium on the exposed or upper side, the membranous inner
peridium often remaining about the spore-mass; columella also white,
globose or depressed-globose; capillitium generally colorless, some-
what branched, especially above; spores dark violaceous, verruculose,
10-12 /x.

A very beautiful species, recognizable at sight when unopened by
the peculiar chocolate brown color; the sporangia smaller than in
D. radiatum. When opened, the snow-white flower-like figure, flat
against the substratum, is definitive. Very near D. trevelyani but the
dehiscence is more regular, and the middle crystalline layer is lacking
in the sporangium wall.

Var. luteum Meylan differs from the typical form in its chamois or
yellowish color.

Colorado, Washington, Oregon, California; Europe.

DIDERMA 135

19. DlDERMA ANTARCTICUM (Speg.) Stwgis

Mycologia 8 : 37. 1916.
(as D. antarctica)

1887. Licea antarctica Speg., Bot. Acad. Nac. Cienc. Cord. 11 : 56.

Sporangia crowded, sessile, subglobose, smooth, mottled brown,
0.7-1 mm. in diameter; sporangium wall cartilaginous but brittle,
cream colored on the inside, the two layers closely adhering and
enclosing deposits of white lime granules; columella large, hemispher-
ical, cream colored, bearing numerous spine-like processes; capillitium
rigid, purplish, with irregular membranous expansions; spores dark
purplish brown, with a paler band of dehiscence, closely spinulose,
often with dark ridges, 11-12 \x.

Our only specimens are from Professor Plunkett of the University
of California at Los Angeles, determined by Miss Lister. The outer
peridium is mottled pinkish buff, crustaceous, and the spores are
14-16 ix. They may represent a distinct species.

Southern California (?), Chile.

20. DlDERMA IMPERIALE Emoto

Bot. Mag. Tok. 43 : 172. 1929.
(as D. imperialls)

Sporangia gregarious, hemispherical or appressed, umbilicate below,
about 1 mm. in diameter, dusky neutral gray * to olivaceous black *,
usually sessile, but often stalked, the total height of the stalked spo-
rangia about }■& mm.; sporangium wall simple, clear brown, encrusted
with amorphous calcium granules; stalk dark brown, cylindrical or
awl-shaped, striate longitudinally, 0.15 mm. tall; columella lacking;
capillitium colorless, sparsely branched, very slender, often bearing
calcium granules and round, wart-like, refractive enlargements; spores
globose, clear violet-brown, warted, 10 fx.

The simple sporangium wall indicates the subgenus Leangium.
The original description states that the capillitium is "about 0.17 /x
thick," an obvious error. The illustration shows it to be very delicate,
however, and this feature, and the absence of a columella, seem
to be the distinctive characters.

Japan. Known only from a single collection growing on mosses on
the trunk of a living Cryptomeria.

136 THE MYXOMYCETES

21. Diderma radiatum (L.) Morgan

Jour. Cin. Soc. Nat. Hist. 16 : 151. 1894.
PI. IX, Figs. 204, 205.

1763. Lycoperdon radiatum L., Sp. Plant, ed. 2. 1654.

1797. Didymium stellar e Schrad., Nov. Gen. PI. 21.

1801. Diderma stellare (Schrad.) Pers., Syn. Meth. Fung. 164.

1801. Diderma umbilicatum Pers., Syn. Meth. Fung. 165.

1803. Diderma crassipes Schum., Enum. PI. Saell. 2 : 196.

1804. Reticularia umbilicata (Pers.) Poiret, in Lam. Encycl. 183.

1809. Leangium stellare (Schrad.) Link, Mag. Ges. Nat. Fr. Berl. 3 : 26.

1815. Didymium geaster Link, Mag. Ges. Nat. Fr. Berl. 7 : 42.

1827. Cionium stellare (Schrad.) Spreng., Syst. Orb. Veg. 4 : 529.

1827. Cionium umbilicatum (Pers.) Spreng., Syst. Orb. Veg. 4 : 529.

1836. Diderma carmichaelianum Berk., in Sm., Engl. Fl. 5 (2) : 311.

1869. Didymium complanatum Fuckel, Symb. Myc. 341.

1873. Diderma concinnum Berk. & Curt., Grev. 2 : 52.

1875. Chondrioderma radiatum (L.) Rost, Mon. 182.

1877. Chondrioderma carmichaelianum (Berk.) Cooke, Myx. Gt. Brit. 42.

Sporangia scattered, depressed-globose, sometimes also flattened
below, stipitate, smooth or slightly corrugate, ashen or brownish drab,
rarely reddish or white, about 1 mm. in diameter, the peridium dehisc-
ing irregularly or somewhat radiately from above downwards, the
segments reflexed, the inner layer not distinguishable or inseparable;
stipe short, stout, brownish, sometimes almost lacking; hypothallus
not conspicuous, but sometimes sufficient to connect the bases of
adjacent stipes; columella large, hemispherical or globose, pallid or
yellowish; capillitium abundant, of slender, generally simple, colored
threads, paler at the furcate tips; spores dark violaceous, minutely
roughened, 8-1 1 /z.

Rare on rotten logs in the forests; September. Easily recognized
by the short-stiped, ashen sporangia which before dehiscence indicate
by delicate tracings the lines which subsequent cleavage is to follow.
In texture the peridium resembles that of D. floriforme.

The Linnaean description on which to base the specific name D. radi-
atum is wholly inadequate. It appears also by the testimony of Linne
fits, that Lycoperdon radiatum L. is a lichen and the name is so applied
by Persoon. But in the Linnaean herbarium preserved at London,
teste Lister, the original type of Lycoperdon radiatum L. may yet be
seen to the confusion of fits, Persoon and other followers of Schrader.

The var. umbilicatum Meylan (Ann. Cons. Bot. Gen. 1913 : 312)
with pale, flattened, umbilicate sporangia, has often been given specific
distinction as D. umbilicatum Pers. ; the var. rubrum Ronn (Schr. Nat.
Ver. Schles.-Holst. 15 : 59, 1911) is said to have grayish pink spo-

DIDERMA 137

rangia and pink lime deposits. The var. macrosporum Meylan (Bull.
Soc. Vaud. Sc. Nat. 56 : 68, 1925) is said to have spores 14-15 fi.

Pennsylvania, Virginia, Ohio, Iowa, Colorado, Montana, Washing-
ton, Oregon; Europe generally, North Africa, Australia, India, Japan.

22. Diderma roanense (Rex) Macbr.

N. A. Slime-Moulds 104. 1899.
PI. IX, Figs. 206, 207.

1893. Chondrioderma roanense Rex, Proc. Ac. Nat. Sc. Phila. 368.

Sporangia scattered, discoidal, thin, flattened or slightly convex
above, plane or plano-concave below, umber-brown, stipitate, the outer
peridium smooth, brittle, rupturing irregularly, the basal fragments
somewhat persistent, concrete with the inner peridium, which is pure
white, except near the columella, and punctate; stipe short, variable,
longitudinally ridged, jet-black; hypothallus not evident; columella
flat, discoidal, pale ochraceous; capillitium sparse, white or colorless,
composed of simple, rarely forked, sinuous threads occasionally joined
by lateral branches; spores dark violaceous, minutely but distinctly
warted, 12-14 ju.

This species is readily distinguished by its color. The sporangia,
found on rotten wood, are large, 1 mm. in diameter, brown, and have
thick, persistent walls. Doctor Rex considered that the species differs
from other related forms not only in color, but in the well-marked
discoidal columella and the jet-black irregular stipe. It is perhaps
most nearly related to D. radiatum.

Maine, New Hampshire, Tennessee, Colorado; Switzerland.

23. Diderma lucidum Berk. & Br.

Ann. Mag. Nat. Hist. 3 ser. 7 : 380. 1861.

1877. Chondrioderma lucidum (Berk. & Br.) Cooke, Myx. Gt. Brit. 42.
1892. Chondrioderma carmichaelianum (Berk.) Cooke ex Mass., Mon. 202, in
part.

Sporangia scattered, subglobose, flattened beneath, 0.8 mm. in
diameter, usually stalked, orange or vermilion, glossy, with pitted
surface, dehiscing irregularly or by four or five lobes that become pale
at the margins; outer layer of sporangium wall translucent orange-
yellow, with scanty deposits of lime on the inner side, closely con-
nected with the yellow inner layer; stalk slender, subulate, brownish
black, 0.2-0.5 mm. high; columella obconic or subglobose, often short-
stalked, rugose, white or cream colored, filled with lime granules;
capillitium a scanty and irregular network of stout, irregular purple-

138 THE MYXOMYCETES

brown threads, often expanded at the axils; spores closely and rather
coarsely warted, 14-16 /z in diameter. Plasmodium orange-yellow.

The bright vermilion sporangia, the distinctive capillitium and large
spores combine to make this a striking and distinctive species. The
above description, adopted in the main from the third edition of the
Lister monograph, has been somewhat modified on the basis of the
examination of some specimens courteously furnished by Miss Lister.

Rare and local. Wales, England (?), Germany, Ceylon (?). Not
known from North America.

24. Dederma floriforme {Bull.) Pers.

Roem. N. Mag. Bot. 1 : 89. 1794.
PI. IX, Figs. 208, 209.

1791. Sphcerocarpus floriformis Bull., Champ. 142.

1791. Stemonitis floriformis (Bull.) Gmel., Syst. Nat. 2 : 1469.

1797. Didymium floriforme (Bull.) Schrad., Nov. Gen. PI. 21.

1801. Lycoperdon floriforme (Bull.) With., Brit. PI. ed. 4. 4 : 379.

1803. Diderma spurium Schum., Enum. PI. Saell. 2 : 197.

1804. Reticular ia floriformis (Bull.) Poiret, in Lam. Encycl. 6 : 182.
1809. Leangium floriforme (Bull.) Lk., Mag. Ges. Nat. Fr. Berl. 3 : 26.
1814. Leangium lepidotum Ditm., in Sturm., Deutsch. Fl. Pilze 2 : 43.
1827. Cionium floriforme (Bull.) Spreng., Syst. Orb. Veg. 4 : 529.
1827. Cionium lepidotum (Ditm.) Spreng., Syst. Orb. Veg. 4 : 529.
1829. Diderma lepidotum (Ditm.) Fr., Syst. Myc. 3 : 100.

1875. Chondrioder ma floriforme (Bull.) Rost., Mon. 184.

Sporangia crowded, generally in dense colonies, globose, smooth,
ochraceous brown, varying from nearly white to umber, stipitate;
peridium thick, cartilaginous, splitting from above into several petal-
like lobes, which speedily become reflexed exposing the pale brown
inner surface of the peridium and swarthy spore-mass, the inner perid-
ium not separable; stipe concolorous, about equal to the sporangium;
hypothallus generally well developed, but thin, membranaceous, com-
mon to all the sporangia; columella prominent, globose or cylindric,
often constricted below, and prolonged upward almost to the top of
the spore-case; capillitium of slender, delicate, sparingly branched
threads; spores dark violaceous brown, paler on one side and sparsely
and irregularly studded with large, blunt warts, 10-11 fx.

Not uncommon, especially on rotten oak logs. Easily recognized
by the peculiar form of the fruit, spherical before dehiscence, floriform
after. Unlike most species, this form often fruits in dark places, in
the interior of a log, even in the ground.

New England, Ontario to Iowa, Nebraska, Washington and south;
Europe.

WILCZEKIA 139

25. Diderma rugosum (Rex) Macbr.

N. A. Slime-Moulds 105. 1899.
PI. IX, Figs. 210, 211.

1893. Chondrioderma rugosum Rex, Proc. Acad. Nat. Sc. Phila. 369.

Sporangia gregarious, scattered, stipitate, white or ashen, rugulose
over the whole surface, the ridges marking the lines of subsequent
rupture or dehiscence; peridium thin, papyraceous; stipe well de-
veloped, equal to or exceeding the sporangium, subulate, almost black;
hypothallus none; columella distinct, globose, generally white, some-
times small, sometimes penetrating the sporangium to one-half the
height; capillitium white or colorless, the filaments freely forked and
combined by lateral branches into a loose network attached to the
columella and basal wall below and the upper sporangial wall above;
spores violaceous brown, warted, 8-10 ix. Plasmodium gray.

This species is well designated rugosum, and is recognizable at sight
by its wrinkled, areolate surface. Related to D. radiatum in the pre-
figured dehiscence, but otherwise very distinct. Likely to be over-
looked as a prematurely dried physarum.

Var. sessile Brandza (Bull. Soc. Myc. Fr. 44 : 266, 1929) as described,
differs so greatly from the typical form as to suggest specific distinc-
tion. The sporangia are small, 0.4-0.8 mm., sessile, the peridium dis-
tinctly double, the columella usually rudimentary or lacking, the
spores 12-14 ^.

Var. asiatica Skvortzow 1931, does not seem to differ from the typi-
cal form in any significant respect.

Rare. North Carolina, Florida, Iowa, West Indies; Europe, Asia.

5. Wilczekia Meylan
Bull. Soc. Vaud. Sc. Nat. 56 : 68. 1925.

Sporangia ovoid, elliptical or subspherical, often somewhat com-
pressed transversely; peridium simple, membranous, the entire sur-
face covered with amorphous lime granules and plasmodic particles;
capillitium of branched and anastomosing colored filaments similar
to those of the Didymiaceae; columella present or absent; spores black-
ish brown. Described as having the capillitium and columella of
Diachea, but differing from that genus and from Leptoderma in the
opaque limy peridium wall.

A single species:

140 THE MYXOMYCETES

Wilczekia evelin^: Meylan

Bull. Soc. Vaud. Sc. Nat. 56 : 69. 1925.

Sporangia sessile, ovoid or elliptical, rarely subspherical, often
compressed transversely, 0.3-0.5 mm. tall, dull gray, somewhat rugu-
lose or furrowed, darker or brownish below, usually grouped in twos
or threes; peridium membranous, single, the entire surface covered
with brownish plasmodic particles, and irregular or more or less star-
like calcareous granules 2-4 \x in diameter; capillitium of branched,
anastomosing filaments, similar to those of Didymium, of the same
color as the spores except at the extremities, which are hyaline, so
that the surface of the capillitial mass is grayish, the forkings forming
triangular enlargements sometimes containing the same materials as
those deposited on the peridium; columella usually lacking, sometimes
well developed and then calcareous; spores sooty, dull, scarcely trans-
parent, spiny, 9-11 (x.

The dehiscence is irregular, by the fragmentation of the upper part
of the peridium, the capillitium, which adheres to the peridium only
at the base, retaining its shape as in some species of Physarum. The
author speaks of "amorphous crystals" of lime, and later of "calca-
reous crystals of irregular form or star-shaped or granular." The infer-
ence is that they are not regularly star-shaped, as in Didymium.

Jura Mountains, Switzerland.

6. Lepidoderma de Bary
in Rost. Versuch 13. 1873.

Sporangia stalked, sessile or plasmodiocarpous; peridium cartilagi-
nous, more or less covered with large calcareous scales which are
either superficial or immersed in lenticular cavities; capillitium non-
calcareous.

The crystalline scales are soluble in weak hydrochloric acid, and are
enclosed in a delicate sac. Could the outer peridium be seen in process
of formation it would probably be found to be made up of an ecto-
sarcous foam in whose cavities the excreted calcium is crystal-
lized.

The taxonomy of this small genus is difficult. L. tigrinum, the com-
monest species, is rather clearly marked, but descriptions of the other
species are not in agreement, and sometimes specimens distributed
by those who have published on them are not in entire accord with
the descriptions. The following treatment is based on a careful
comparison of the material available with the published descrip-
tions.

LEPIDODERMA 141

KEY TO THE SPECIES OF LEPIDODERMA

a. Sporangia stipitate, stipe bright orange-brown; rarely

sessile on an orange-brown hypothallus 1. L. tigrinum

a. Typically sessile or plasmodiocarpous; rarely stipitate and

stipe then dark b

b. Subglobose, pulvinate or short-plasmodiocarpous; spores

10-13 fj, 2. L. chailletii

b. Typically plasmodiocarpous; spores usually larger c

c. Spores 15-18 /j.; capillitium usually vesicular 3. L. granuliferum

c. Spores 11-15 n\ capillitium not vesicular 4. L. carestianum

1. Lepidoderma tigrinum (Schrad.) Rost.

Versuch 13. 1873.
PI. X, Figs. 212, 213.

1797. Didymium tigrinum Schrader, Nov. Gen. Plant. 22.

1801. Physarum squamulosum Pers., Syn. Meth. Fung. 174.

1801. Physarum tigrinum Pers., Syn. Meth. Fung. 174.

1808. Trichia squamulosa Poiret, Lam. Encycl. 8 : 53.

1808. Trichia tigrina Poiret, Lam. Encycl. 8 : 53.

1827. Leangium squamulosum Fr., Stirp. Femsj. 83.

1829. Didymium rufipes Fr., Syst. Myc. 3 : 116.

1836. Diderma citrinum Berk., Sm. Engl. Flora 5 (2) :310, non Fr.

1892. Lepidoderma fulvum Mass., Mon. 253.

Sporangia scattered, rather large, often 1-2 mm. in diameter,
hemispherical-depressed, stipitate, umbilicate beneath; peridium shin-
ing, olivaceous or purplish, tough, covered more or less abundantly
with flat, circular or angular scales; stipe 1-2 mm. tall, stout, furrowed,
dark brown, but containing calcareous deposits, tapering upward, and
continued within the peridium as a pronounced more or less calcareous
columella; hypothallus more or less prominent, yellowish or brownish;
capillitium dark, purplish brown, of sparingly branching threads radi-
ating from the columella; spores dull purplish brown, minutely spinu-
lose, 10-13 fi. Plasmodium orange.

A singular species, easily recognized by its peculiar, placoid scales,
large and firmly embedded in the peridial wall. The internal struc-
ture is essentially that of Diderma or Didymium. The species occurs
in hilly or mountainous regions, on moss-covered logs. The Plasmodium
is yellow, some part of it not infrequently remaining as a venulose
hypothallus connecting such sporangia as are near together.

Meylan records a dwarf phase, form microcarpon, with sporangia
only 0.5 mm. in diameter, from the Alps, also a form gracile, with long
slender stem, from the Jura Mountains.

New England to British Columbia and Oregon; rare in the east,
common on the Pacific coast; Europe, Japan.

142 THE MYXOMYCETES

2. Lepidoderma chailletii Rost.

Mon. 189. 1875.

1911. Lepidoderma carestianum Rost. var. chailletii (Rost.) List., Mycetozoa
ed. 2. 140.

Sporangia subglobose or pulvinate, or forming short plasmodiocarps,
crowded and more or less coalescent, or merely gregarious, large,
1-1.5 mm. broad, drab or dull gray, sparsely sprinkled with white
tetrahedral or irregular scales; peridium thin, more or less translu-
cent, rugulose, dull brown or yellowish, persistent; columella clavate
or scarcely developed; capillitium abundant, under the lens purple-
brown, sparingly branched, even, slender, without calcareous deposits
or vesicles; spores minutely warted, fuliginous, 10-13 /*. Plasmodium
dirty white.

Similar to L. carestianum, but differing in the size and habit of the
sporangia, in the more uniform capillitium and in the size, color and
surface characters of the spores.

Washington, California; Europe.

3. Lepidoderma granuliferum (Phill.) R. E. Fr.

Arkiv for Bot. 6 (7) : 3. 1906.
PI. X, Figs. 214, 215, 216.

1877. Didymium granuliferum Phill., Grev. 5 : 114.

1891. Amaurochcete minor Sacc. & Ell., Michelia 2 : 566.

1892. Badhamia granulifera (Phill.) Massee, Mon. 321.

1911. Lepidoderma carestianum (Rabenh.) Rost. var. granuliferum Lister,
Mycetozoa ed. 2. 140.

Sessile, plasmodiocarpous, the peridium dark, covered with dull
cinereous scales, appearing light drab under lens; columella small,
dark; capillitium rough, dark or pale and often with vesicular expan-
sions at the axes, which enclose calcareous deposits; spores clear brown,
rather sparsely covered with distinct dark warts, 15-20 n in diam-
eter.

A puzzling form, very variable, and undoubtedly approaching
L. carestianum, but apparently differing constantly in the very large
spores. The marking of the latter differs from the marking on the
spores of carestianum in that the warts are longer and more slender,
more spinulose. Lister emphasizes the calcareous inclusions in the
capillitium, but this feature seems to be inconstant. Phillips' original
description gives the spore measurements as 22-25 n, larger than in
any of the material so referred in our collection. Harkness No. 35,

LEPIDODERMA 143

from Utah, in Ellis collection, N. Y. Bot. Gard., belongs here. A col-
lection from Washington, which otherwise seems to belong here, has
short, irregular, brownish stipes.

Washington, California, Utah; Sweden, Switzerland. Alpine, and
apparently uncommon.

4. Lepidoderma carestianum Rost.

Mon. 188. 1875.
PI. X, Figs. 217, 218, 219.

1862. Reticularia carestiana Rabenh., Fung. Eur. Ex. No. 436. Not pub-
lished.

Fructification in the form of flat, pulvinate plasmodiocarps, or
rarely sporangiate, the sporangia sessile, ellipsoidal, elongate, irregu-
lar, confluent, brown or brownish gray, the peridium covered more or
less completely with dull white or yellowish crystal-like scales; colu-
mella, where visible, yellowish brown, calcareous; capillitium coarse,
rigid, more or less branched and united, or colorless, delicate, forming
a definite net; spores distinctly warted, purple, 11-15 ix. Plasmodium
black.

The plasmodial colors of this species and L. chailletii are quoted
from Lister with some misgiving, since the other characters of these
two species are based upon Meylan's treatment, which seems more in
accord with the material available for study. The difference in spore-
size between the two species is not distinctive, since the ranges over-
lap, but in general, the sporangiate forms have small spores and the
plasmodiocarpous forms large spores, while the average spore-size of
L. granuliferum is well beyond either. Amaurochcete minor Sacc. & Ell.,
cited by Lister as a synonym of the present species, is represented in
the Ellis collection at the New York Botanical Garden by two collec-
tions made by Harkness in Utah. The spores range from 15-18 ix in
diameter, averaging 16.3 /j.. In this and in other respects, the material
agrees with L. granuliferum as here understood.

New Hampshire, Washington, California; Europe.

Lepidoderma mandshurica Skvortz. (Phil. Jour. Sc. 46 : 88, 1931) is
described as follows: "Sporangia forming short, subglobose or elon-
gate pulvinate plasmodiocarps, 0.5 mm. to 5 cm. long, 0.5 to 5 mm.
broad, silvery gray, clothed with brilliant brownish threads, branched
and anastomosing. Spores brown-violet, smooth, 6.8 to 7.2 /x." The
illustrations show a flattened, pulvinate, circular to irregularly ex-
panded fructification. Apparently differing from L. carestianum Rost.
mainly in the gray color and the much smaller spores.

144 THE MYXOMYCETES

7. Leptoderma G. Lister
Jour. Bot. 51 : 1. 1913,

Fructification sporangiate, the walls membranous above, thickened
with dark granular deposits below; calcareous deposits restricted to
scales embedded among the basal granules; capillitium netted; spores
purplish gray.

A single species:

Leptoderma irtdescens G. List.

Jour. Bot. 51 : 1. 1913.

Sporangia scattered or loosely clustered, subglobose, sessile or rarely
short-stalked, grayish purple, glossy, iridescent, 0.5-0.8 mm. in di-
ameter; sporangium wall nearly hyaline above, purplish below, where
it is thickened with granular deposits and refuse material, often in-
cluding crystalline flakes of lime 2-15 li in diameter; stalk, when pres-
ent, stout, dark, spreading below into a dark hypothallus; columella
present or absent, dark and convex when present; capillitium a persist-
ent network of arching or flexuose dark purple threads radiating from
the base, the tips and bases colorless or pale, the latter often expanded
or tubular and sometimes enclosing granular matter; spores purplish
gray, spinulose, 10-11 fx. Plasmodium gray or drab.

Certain collections from Oregon and California possibly represent
somewhat aberrant forms of this species. The fructifications vary
from subglobose sporangia to short plasmodiocarps. The lime is re-
stricted to the basal portion or even to the hypothallus, but does show
occasional crystalline plates. The spores are a trifle large, 11-13 fx.

Oregon? California? Europe.

Order STEMONITALES

Fructification wholly non-calcareous, except in a single genus
(Diachea) in which the stipe and columella, but neither the capil-
litium nor the peridium, are calcareous; capillitium threadlike, of
anastomosing branches either arising from a well-developed columella
or radiating from the base; spores in mass usually black or purple-
brown, less commonly ferruginous.

TCF. V TO THE FAMILIES OF THE STEMONITALES

a. Outer wall of peridium gelatinous; sporangiate; columella

lacking Collodermace^e

a. Peridium membranous, often early fugacious; aethalioid or

COLLODERMACE.E 145

sporangiate; columella typically well developed, rarely

rudimentary or lacking b

b. Fructification aethalioid or of separate sporangia; col-
umella usually prominent, giving rise to a branched
capillitium; in a few forms columella and capillitium
poorly defined Stemonitacejs

b. Sporangia always distinct ; capillitium developed chiefly

or only from the summit of the columella Lamprodermace,£

Family COLLODERMACE^

Sporangiate, sessile or stalked, limeless; peridium duplex, the inner
wall membranous, the outer, gelatinous when moist, with superficial
granular deposits, hard and brittle when dry; capillitium intricate.

A single genus :

Colloderma G. Lister
Jour. Bot. 48 : 312. 1910.

With the characters of the family. The one species was originally
described by Lippert as a didymium on the basis of calcareous de-
posits in the sporangium wall. These have not been observed in
numerous later collections. A distinctive genus, well regarded as the
type of a separate family.

A single species:

Colloderma oculatum (Lipp.) G. List.

. ^_ . ■— — - j ^

Jour. Bot. 48 : 312. 1919. Vj,

PI. X, Figs. 220, 221, 222.

1894. Didymium oculatum Lipp., Verh. Zool.-Bot. Ges. Wien 44 : 72.

Sporangia gregarious, globose, subglobose or pulvinate, sessile or
short-stipitate, olivaceous or brown, becoming black when old and dry,
smooth and shining, the outer peridium gelatinous, thickened by mois-
ture, hyaline; stipe, when present, thick, dark brown; columella none;
capillitium resembling that of Didymium, purplish brown, colorless at
the tips, often duplex, the darker interior portion surrounded by a
hyaline sheath, the latter usually broken up into segments or frag-
mented; spores spinulose, fuscous, 11-13 /j..

Swollen by immersion in water the sporangia take on the eye-like
appearance which suggested the specific name.

New Hampshire, Vermont, Oregon; Europe, Australia, Japan.

146 THE MYXOMYCETES

Family STEMONITACE^

Fructification aethalioid or of separate and distinct sporangia;
capillitium usually abundant, typically in the form of dividing and
anastomosing branches arising from all parts of the columella, the
latter sometimes lacking or indistinct; hypothallus membranous, often
common to a group of sporangia. The first two genera are of doubtful
affmity with the others.

KEY TO THE GENERA OF THE STEMONITACE^E

a. Stipe and columella calcareous, rarely waxy 1. Diachea

a. Wholly non-calcareous b

b. Fructification aethalioid c

b. Fructification sporangiate e

c. Capillitial threads unbranched, united into columnar cords

and attached to both base and peridium; columella lacking. ... 2. Schenella

c. Capillitium branched, dendroid d

d. Columellas obscure or lacking; capillitium not vesicular. . . 3. Amaurochcete
d. Columellas distinct above, merging below; capillitium vesic-
ular 4. Brefeldia

e. Tips of capillitial branches united to form a more or less com-
plete surface net 5. Stemonitis

e. Surface net lacking, or scantily and imperfectly developed .... 6. Comatricha

1. Diachea Fries
Syst. Orb. Veg. 1 : 143. 1825.

Sporangia distinct, globose or cylindric, usually stipitate; peridium
thin, iridescent; stipe and columella charged with lime, white to orange,
rigid, thick, tapering upward; capillitium of delicate threads free from
lime, radiating from various points on the columella, branching and
anastomosing as in Comatricha to form a more or less intricate net-
work, the ultimate branchlets supporting the peridial wall.

Rostafinski placed this genus near the Didymieae on account of the
calcareous columella and the non-calcareous capillitium. On the other
hand the structure of the capillitium and the iridescent simple peridium
ally Diachea to Lamproderma and the Stemonitaceae, the only dis-
tinction being the calcareous stem. It is simply an intermediate genus
to be placed here more conveniently than anywhere else in what is of
necessity a linear arrangement.

KEY TO THE SPECIES OF DIACHEA

a. Lime deposits white b

a. Lime deposits orange, or lacking /

b. Sporangia typically cylindrical I. D. leucopodia

b. Sporangia ovate, globose or hemispherical c

DIACHEA 147

c. Stalks equalling or exceeding height of sporangia d

c. Stalks very short, sometimes lacking e

d. Spores sparsely and irregularly warted 2. D. bulbillosa

d. Spores with numerous dark warts and lines forming an im-
perfect reticulation 3. D. splendens

e. Spores spinulose or warted 4. D. radiata

e. Spores distinctly warted-reticulate 5. D. subsessilis

f. Calcareous deposits orange or orange-yellow 6. D. thomasii

f. Lime lacking; stem translucent, waxy or black, with wax

deposited as a collar at junction with sporangium 7. D. cerifera

1. DlACHEA LEUCOPODIA (Bull.) Rost.

Mon. 190. 1875.
PL X, Figs. 226, 227, 228.

1791. Trichia leucopodia Bull., Champ. 121, PI. 502, fig. 2.

1797. Stemonitis elegans Trentep. in Roth, Cat. Bot. 1 : 220.

1801. Stemonitis leucostyla Pers., Syn. Meth. Fung. 186.

1805. Stemonitis leucopodia DC, Fl. Fr. 2 : 257.

1825. Diachea elegans Fr., Syst. Orb. Veg. 143.

1892. Diachea confusa Massee, Mon. 259.

Sporangia rather closely gregarious, metallic blue or purple-irides-
cent, cylindric or ellipsoidal, obtuse, subumbilicate below, stipitate;
stipe short, much less than one-half the total height, snow-white,
tapering upward; hypothallus white, venulose, forming an open net-
work over the substratum from which the sporangia arise; columella
thick, cylindric, tapering, blunt, terminating below the apex, white;
capillitium springing from every part of the columella, of slender
threads, brown, flexuous, branching and anastomosing to form an
intricate net; spores in mass nearly black, by transmitted light dull
violaceous, minutely roughened, 8-11 ix.

A very beautiful species; common in the United States. Easily
recognized, amid related forms, by its snow-white stem and cylindri-
cal sporangium. Fries adopted the specific name proposed by Trente-
pohl and wrote D. elegans, simply because to him the peridium was
"admodum elegans."

The peridium is exceedingly thin and early deciduous; the stipe
long-persistent. The Plasmodium, dull white, was observed by Fries
at the beginning of the century; "morphoseos clavem inter myxo-
gastres hoc genus primum mihi subministravit." Rostafinski wrote
the specific name leucopoda, in which spelling he is followed by Massee
and Lister. Bulliard wrote leucopodia and there seems to be no reason
for changing the spelling.

This species, as the diacheas generally, affects fallen sticks and

148 THE MYXOMYCETES

leaves in orchards and forests and even spreads boldly over the foliage
and stems of living plants.

Var. globosa Lister, with globose or subglobose sporangia, is con-
nected with the typical form by continuous series. Apparently much
less common and usually occurring with it. Distinguished from
D. bulbillosa by the spores.

Cosmopolitan.

2. Diachea bulbillosa {Berk. & Br.) List.

Jour. Bot. 36 : 165. 1898.
PI. X, Fig. 235.

1873. Didymium bulbillosum Berk. & Br., Jour. Linn. Soc. 14 : 84.
1909. Diachczella bulbillosa Hohnel, Sitzungsb. Akad. Wiss. Wien, Math. -Nat.
Kl. (I) 118 :437.

Sporangia gregarious, globose, stipitate, small, smooth, 0.3-0.4 mm.
in diameter, and 1.5 mm. or less tall; stipe conical, white or sometimes
brown; capillitium of purple-brown threads united to form a lax net;
spores violet-gray, rather sparsely and irregularly warted, the warts
dark and varying in size, 7-11 fx.

Said to be common in southern Asia. Specimens from Ontario, col-
lected by Miss Currie and reported by her in the "Slime-molds of
Ontario," show spores rather variable in size, mostly between 8.1 and
9.6 ju, and averaging about 9 ju, not 7.8 fx as she states. A collection of
Morgan's from Ohio, labelled by him Diachcea longipes Morgan, with
dark, sparsely warted spores, 7.5-8 n, is also this species.

Ontario, Ohio; southern Asia.

3. Diachea splendens Peck

Rept. N. Y. State Mus. 30 : 50. 1878.
PL X, Figs. 229, 230.

1925. Diachea bulbillosa (Berk. & Br.) List. var. splendens G. List., Mycetozoa
ed. 3. 103.

Sporangia gregarious, metallic blue with brilliant iridescence, glo-
bose, stipitate, 0.3-0.6 mm. in diameter, a millimeter or more tall;
stalk conical, about equal to the diameter of the sporangium, tapering
upward; hypothallus white, venulose, a network supporting the snowy
stipes; columella white, cylindric, obtuse, passing the center; capil-
litium lax, of slender brown threads anastomosing to form a network;
spores in mass black, by transmitted light pallid, with very coarse,
dark warts and ridges forming an incomplete reticulation on the sur-
face, 7-10 /x.

This is perhaps the most showy species of the list. The globose,

DIACHEA 149

brilliantly iridescent sporangia are lifted above the substratum on
snow- white columnar stalks; these are again joined one to another by
the pure white vein-like cords of the reticulate hypothallus. The Plas-
modium may spread very widely over all sorts of objects that come in
the way, dry forest leaves and sticks, or the fruit and foliage of living
plants. Closely resembling D. leucopodia, but differing in the globose
sporangia, it may be instantly recognized under the lens by its coarsely
papillate and subreticulate spores.

Miss Lister regards this as a variety of D. bulbillosa. So far as our
scanty material of the latter species enables us to judge, they are clearly
distinct.

Not common. New York, Pennsylvania, Ontario, Ohio, Iowa,
Nebraska.

4. Diachea radiata G. Lister & Petch

Jour. Bot. 54 : 130. 1916.

Sporangia loosely clustered, or crowded in large colonies, hemispher-
ical or globose, 0.4-0.5 mm. in diameter, sessile or rarely stalked,
iridescent-gray or bronze, seated on a white hypothallus; sporangium
wall membranous, colorless; stalks, when present, short, stout, fur-
rowed, white, calcareous; columella white, convex, conical or short-
cylindrical; capillitium a network of purple-brown threads radiating
from the columella; spores pale violet-gray, spinulose or warted, 8-11 fx.
Plasmodium orange-yellow.

Apparently close both to D. subsessilis, from which it is separated by
spore characters, and to the globose phase of D. leucopodia, from which
it would seem to differ in the color of the sporangium wall and that of
the Plasmodium. Specimens not seen.

Ceylon, southern Nigeria.

5. Diachea subsessilis Peck

Rept. N. Y. State Mus. 31 : 41. 1879.
PI. X, Figs. 231, 232.

Sporangia gregarious or closely crowded, small, about 0.5 mm., dull
iridescent-blue or greenish gray, globose or depressed-globose; stipe
generally very short, reduced sometimes to a mere persistent cone,
white or pale brown; columella obsolescent or reduced to a conical
intrusion of the stipe; capillitium radiating from the stipe, brown, con-
sisting of branching, anastomosing threads, paler at the tips; hypo-

150 THE MYXOMYCETES

thallus very scanty or none; spores distinctly reticulate-warted, violet-
brown, paler under the lens, 10-12 /x. Plasmodium yellow.

Somewhat resembling D. splendens, but duller in hue, more oliva-
ceous, usually with a much shorter stalk and almost without columella.
The spores are quite different, the network composed of lines of warts,
but much more regular than in splendens.

According to Lister, Lamproderma fuckelianum Rost. is probably
this species. Rostafinski's figure suggests that this may be so, but in
view of the uncertainty, Peck's name is retained.

Rare. Connecticut, New York, Iowa, Colorado; Europe, Java,
Ceylon.

6. Diachea thomash Rex

Proc. Acad. Nat. Sc. Phila. 1892 : 329.
PL X, Figs. 233, 234.

Sporangia gregarious, more or less crowded, purple and bronze,
iridescent, globose, sessile or short-stipitate; stipe, when present, very
short, thick, tapering rapidly upward, orange; hypo thallus orange,
prominently venulose, continuous; columella ochre yellow, rough,
cylindric or conical, tapering upward to one-half the height of the
sporangium, obtuse; capillitium lax, of slender brown rigid threads,
radiating from the columella in every direction, anastomosing to form
a loose, large-meshed network; spore-mass brown; spores by trans-
mitted light violaceous, minutely, unevenly warted, 11-13 /x.

The peculiar orange color of the calcareous deposits in stipe and
columella easily distinguishes this species. The capillitium is also dis-
tinctive, rigid, simple and comparatively scant, lamprodermoid. Rex
calls attention to the fact that under low magnification the spores
appear spotted; but the spots are occasioned simply by the closer
aggregation, at particular points, of the ordinary papillae.

A southern species. Mountains of North Carolina and Tennessee.

7. Diachea cerifera G. List.

Jour. Bot. 51 : 3. 1913.
PI. X, Fig. 236.

1911. Lamproderma columbinum (Pers.) Rost. var. sessile Lister, Mycetozoa
ed. 2. 165.

Sporangia scattered or in small clusters, limeless, stalked, subglobose
or ovoid, 0.7-1.2 mm. in diameter, shining iridescent brownish purple;
sporangium wall membranous, hyaline, often yellowish and persistent
below; stalk brownish black, yellowish brown or white, 0.2-0.6 mm.

SCHENELLA 151

tall, sometimes with a thick yellow waxy collar at apex just below the
sporangium; columella none, but the base of the sporangium broad and
flat, the capillitium of rigid, sparsely branched and anastomosing
purple filaments arising from this in brush-like fashion; spores pur-
plish gray, spinulose, 10-18 n in diameter. Plasmodium white.

Scarcely a diachea as here defined; suggesting Lamproderma, but
without a columella. The spore range as given by Miss Lister seems un-
duly great. Specimens from Switzerland have spores 11-13 /x, rather
sparsely spinulose, and waxy stems, although lacking the collar. It
seems possible that Miss Lister's genus Leptoderma might be so
emended as to accommodate this distinctive species, but pending
further study it may remain here.

Europe, Japan.

2. Schenella Macbride
Mycologia3 : 39. 1911.

Fructification aethalioid, depressed, flat, covered by a fragile, con-
tinuous crust; capillitium of simple threads twisted together to form
vertical, closely arranged columns passing from the base to the outer
peridium as if supporting it. Spores fuscous black.

A single species :

Schenella simplex Macbride

Mycologia3 : 39. 1911.
PI. X, Figs. 237, 238; PL XXI, Figs. 563, 564.

yEthalium oval, about 4 cm. long by 2 cm. wide and 3 mm. thick;
peridium pallid, soon disappearing; capillitium abundant, dark brown,
exposed by the breaking up of the crust-like peridium and then having
the appearance of a stemonitis colony, each column being made up of a
number of tubular, smooth, unsegmented threads twisted together so
as to form a cord, and in some instances covered in whole or part by a
delicate common sheath; spores very dark, spherical, ovate or some-
times pyriform, rather coarsely tuberculate, when spherical 5-6^ in
diameter.

A very curious form, of somewhat doubtful affinities and placed in
the Stemonitaceae on the basis of the dark violet-brown spores and the
dark capillitium. There is no suggestion of columellae in the pillar-like
columns. To the naked eye it suggests an amaurochaate. In addition
to the typical spores, there occur in every mount a few paler, larger,

152 THE MYXOMYCETES

minutely echinulate spores, 8-9 ju in diameter, whose origin is not
apparent.

Type collected in the Yosemite valley, California, August, 1903, by
T. H. Macbride. Known only from the type collection.

3. Amaurochsete Rost.
Versuch8. 1873.

Fructification asthalioid, pulvinate; peridium evanescent, leaving
after its disappearance a mass of irregular stalks and branches, forming
the capillitium complex, seated on a common, dark, membranous
hypothallus. Capillitium and spores usually black or dark brown in
mass, rarely ferruginous.

In Amaurochaete the individuality of anything like separate sporangia
is not clear. The view afforded, however, by a good vertical section of
a well-developed colony or cushion is interestingly arborescent.
Ragged, dendroid stems arise, dissipated above into an intricate net-
work. The resemblance of the overhead net to that presented by a
stemonitis or comatricha is very striking.

KEY TO THE SPECIES OF AMAUROCHiETE

a. Capillitium rigid, irregular b

a. Capillitium soft, woolly, circinate d

b. Capillitium and spores brown in mass; spores 7.5-9 n,

pale 1. A.ferruginea

b. Capillitium and spores black in mass; spores 12.5-15 \x c

c. Spores spinulose 2. A . fuliginosa

c. Spores strongly reticulate 3. A. trechispora

d. Capillitium composed of numerous stout, often columella-

like branches, giving rise to a dense network 4. A . tubulina

d. Capillitium composed almost wholly of slender flexuose

threads 5. A. comata

1. Amaurochsete ferruginea Macbride & Martin

Jour. Wash. Acad. Sc. 22 : 89. 1932.
PI. XI, Fig. 241.

iEthalium pulvinate, flat, up to 7 cm. in length and 4 cm. in width;
peridium fugacious; hypothallus shining, silvery, extending somewhat
beyond the margin of the aethalium; definite columellas lacking, but
capillitium branching from numerous rigid irregular branches arising
from the hypothallus and soon dissipated into subordinate branches,
the threads dark brown, bearing numerous lighter brown irregular
membranous expansions; spores cinnamon-drab to benzo-brown

AMAUROCHiETE 153

(Ridgway) in mass, pale reddish brown by transmitted light, minutely
warted, 7.5-9 fx.

The structure of the capillitium is very similar to that of A.fuliginosa,
from which species this differs in the brownish color of the capillitium
and in the small, pale, relatively smooth, ferruginous spores, the two
characters together giving the fructification a ferruginous cast in
marked contrast to the black of the other species of the genus.

California, Oregon.

2. Amauroch^ete fuligestosa (Sow.) Macbr.

N. A. Slime-Moulds 109. 1899.
PL XI, Fig. 242.

1803. Lycoperdon fuliginosum Sowerby, Engl. Fungi 257.

1805. Lycogala atrum Alb. & Schw., Consp. Fung. 83.

1815. Strongylium atrum (Alb. &Schw.) Swartz,Hand. K. Svenska Vet. Acad. 1 10.

1817. Strongylium majus Ft., Symb. Gast. 9.

1822. Reticularia strongylium Schw., Schrift. Nat. Ges. Leipz. 1 :35.

1829. Reticularia atra (Alb. & Schw.) Fr., Syst. Myc. 3 : 86.

1875. Amaurochaste atra (Alb. & Schw.) Rost, Mon. 211.

.Ethalia varying in form and size, if on the upper side of the sub-
stratum, pulvinate, if below, pendent and almost stipitate, covered
with a delicate cortex, at first shining, soon dull, black, fragile and
early dissipated; hypothallus long-persisting, supporting the capil-
litium, which is extremely variable, irregular and for its perfection
dependent upon the form assumed by the asthalium, and the condi-
tions under which it matures; sometimes, especially when prostrate
in a very much depressed asthalium, spreading into long fibrous threads,
again, under better conditions, rising in columella-like forms, support-
ing a peripheral net; spores dark brown or black, irregularly globose,
spinulose, 12.5-15 /jl.

Sowerby, in his comment on pi. 257, Eng. Fungi, says: "It appears
to consist of branching threads afiixed to the deal and holding a dense
mass of sooty powder. Over the whole is a thin, deciduous pellicle."
This description seems to be applicable to nothing else. The figure
amounts to little. Fries recognizes the English description, as does
Rostafinski, but both authors adopt the later name given by Albertini
and Schweinitz, simply because of the excellent detailed description
found in the Conspectus.

Common in Europe, and probably not uncommon in this country
wherever pine forests occur; also in Japan. Specimens before us are
from New England and New York, Ohio, Carolina, Colorado and
Canada.

154 THE MYXOMYCETES

3. Amauroch^ete trechispora Macbride &* Martin

Jour. Wash. Acad. Sc. 22 : 89. 1932.
PI. XI, Figs. 239, 240.

iEthalium pulvinate, flat, up to 7 cm. in length; cortex dark, shining,
evanescent, faintly tuberculate as though suggesting the tips of com-
ponent sporangia; hypothallus broadly expanded, persistent, extend-
ing well beyond the borders of the asthalium, silvery, with yellowish
stains and amber globules representing remnants of the presumably
yellow plasmodium; capillitium black, irregular, composed of numer-
ous stout columella-like bases which soon become dissipated into nu-
merous branches, these anastomosing freely; peripheral nets lacking;
spores purplish black in mass, lilaceous brown by transmitted light,
globose, ornamented with a pronounced reticulation formed of wing-
like ridges, the meshes coarse and often unequal, 13-15 /x in diameter,
of which 10-12 ix represents the diameter of the body of the spore, the
balance the ridges of the reticulum.

A well-marked species, related to A . fuliginosa but separated by its
remarkable and striking spores. Based on a collection from northern
Ontario well described by Miss Currie and by her doubtfully referred
to Stemonitis fusca Roth. var. trechispora Torrend. A later collection
from the same region by Dr. Jackson confirms the species. Aside from
the reference to the strongly reticulated spores and the occurrence
on Sphagnum, there is nothing in Torrend's brief description of his
variety to suggest the present species, nor can it be the form described
and illustrated by Jahn as Stemonitis trechispora Torr. It is clearly an
Amaurochaete.

Ontario.

4. Amaurochaete tubulina (Alb. & Schw.) Macbr.

N. A. Slime-Moulds ed. 2. 150. 1922.
PI. XI, Fig. 243.

1805. Stemonitis tubulina Alb. & Schw., Consp. Fung. 102.

1825. Lachnobotus cribrosus Ft., Syst. Orb. Veg. 148.

1917. Amaurochtzte cribrosa (Fr.) Sturgis, Mycologia 9 : 328.

1924. Matruchotiella splendida Skup., Bull. Acad. Pol. Sc. 396.

Plasmodium at first transparent, then white, then rosy, ashen or
gray, finally deepening to jet-black; the aethalium even, thin, variable
in extent from one to ten centimeters, covered by a distinct but thin
transparent cortex, papillate, extended laterally but a short distance
beyond the fructification, fragile, soon disappearing; hypothallus long-
persistent, thin, silvery, supporting the capillitium as if by stipes,
short slender columns, irregular plates, expansions, etc.; capillitium

AMAUROCH^ETE 155

an intricate network, very abundant, elastic, on fall of the peridium
appearing like tiny tufts of wool, the meshes large, but formed as in
Stemonitis, persistent, dull black; spores, under the lens, dull olivaceous
black, minutely roughened, 12-14 /x.

This species differs from A. fuliginosa especially in the capillitial
characters. In the latter species the capillitial branches fray out, and
are only sparingly united into an extremely lax net. In the present
form the net is the thing common to the entire fructification. The
total effect is to lend to the blown-out aethalium a woolly appearance,
entirely unlike that of its congener under the same conditions. But
until fructification is quite mature, the presence of component spo-
rangia below is suggested by the papillose upper surface, and even
after maturity the suggestion of sporangia persists when viewed with a
hand lens.

The amaurochsetes are remarkable in that they appear upon co-
niferous wood, logs or lumber, to all appearance undecayed. The
species just described developed abundantly in August on the recently
decorticated logs of Pinus ponder osa, on the southwestern slopes of
Mt. Rainier, Washington. In logging operations in the locality referred
to, the trees are felled often at a considerable distance from the mill.
The logs are dragged along the ground, the transportation facilitated
by removal of the bark from the new fallen trunk. In a few weeks'
time, affected by alternate rain and sun, the whole surface becomes
marked with hundreds of minute, almost invisible cracks, and it is
in the larger of these that the plasmodium of the present species has
its habitat. The plasmodia rise to fructification, scores at a time,
upon a surface, new and white, showing otherwise no evidence of any
decomposition. Doubtless the persisting cambium, the unused starches,
sugars, the wood of the season yet unlignified, afford easily accessible
nutrition.

When this form was first examined in the laboratory its distinctness
was immediately seen. It was without doubt Fries' Lachnobolus
cribrosus. Under this name, citing Fries' description, specimens were
sent out to various herbaria. Further study of the records, however,
soon convinces one that we are here face to face with the species de-
scribed by Albertini and Schweinitz in their fine "Conspectus." Their
account of the form, evidently often taken and now described with
great care, is entirely clear when read in the presence of the facts.
The matter is discussed fully in North American Slime-Moulds,
2 ed., pp. 151 ff.

Zukal (Verh. Zool.-Bot. Ges. Wien 35 : 335) describes A. speciosa
as a new species. This Saccardo writes down (Syll. Fung. 7 : 399)

156 THE MYXOMYCETES

S. tubulina Alb. & Schw., admitting, however, at the same time, that
as fine an authority as Raciborsky refuses to call Zukal's species either
a stemonite or an amaurochaete, thinking it deserving of generic ap-
oellation of its own. However, A. speciosa Zuk. need not here concern
us. Neither in his description nor figures does Zukal at all approach
the form we study. His species is not an amaurochaete; the size of the
spores suggests that, to say nothing of the capiUitial structure.

In the same volume Saccardo introduces another amaurochaete,
A. minor Sacc. & Ellis (Mich. 2 : 566). This is American, sent from
Utah by our famous pioneer collector Harkness. A portion of this
collection is in the herbarium of the University of Iowa, and is by us
referred to Lepidoderma granuliferum.

Massachusetts, Pennsylvania, Washington; Europe.

5. Amaurochaete comata G. List. &* Brandza

Jour. Bot. 64 : 225. 1926.

^thalia scattered, pulvinate, black and glossy, 5-50 mm. in di-
ameter, on a shining membranous hypothallus; columellae none; cap-
illitium of flexuose, branching, black threads, 1-3 \x in diameter, at-
tached above and below to the membranous walls of the aethalium;
spores 11-14/x in diameter, dark purplish gray, closely warted, some-
what paler and smoother on one side. Plasmodium white.

In general appearance closely resembling A . tubulina, but differing
in the absence of any suggestion of columellae, in the finer and more
flexuose capillitium and in the darker, more distinctly warted spores.
The original description gives the spore-size as 11-12 /i. Spores of
authentic material from Professor Brandza average 13.2 \x and range
from 11-14 ju, occasionally varying beyond these limits.

Rumania, Switzerland.

4. Brefeldia Rostafinski
Versuch8. 1873.

Fructification aethalioid, the constituent veins occupying several
layers, those of the median, and especially of the lowest layer furnished
with columellae which blend beneath; capillitium threads arising from
the columellae and united at adjacent tips by prominent inflated sacs.

The genus Brefeldia is, like some others, difficult to dispose of in
any scheme of classification where linear sequence must be followed.
Rostafinski placed it in an order by itself. Its relationships are on the
one hand with Amaurochaete and on the other with Stemonitis, though
it is easily distinguished from either of these genera. It is intermediate
between the two, but apparently a little nearer Stemonitis.

BREFELDIA 157

Brefeldia maxima (Fr.) Rost.

Versuch9. 1873.
PI. XI, Figs. 244, 245.

1825. Reticularia maxima Fr., Syst. Orb. Veg. 1 : 147.
1848. Licea perreptans Berk., Gard. Chron. 451.

^Ethalium large, four to twenty cm. across, papillate above, violet-
black at first, then purple or purple-brown, developed upon a wide-
spread, silver-shining hypothallus, the peridium at first papillate,
early fugacious, the capillitial branches often falling off with the
spores, leaving the black columellae rising nearly naked from the
base; capillitium abundant, the threads uniting by multifid ends to
surround as with a net the peculiar vesicles; spore-mass dark violet-
black or fuscous, the individual spores paler by transmitted light,
distinctly papillose, 9-12 ju.

A very remarkable species and one of the largest, rivalled only by
Fuligo. To be compared with Reticularia, which it resembles some-
what externally, and with some of the larger specimens of Enteridium.
The Plasmodium, at first white with a bluish tinge, is developed
abundantly in rotten wood, preferably a large oak stump, and changes
color as maturity comes on, much in the fashion of Stemonitis splendens,
leaving a widespread hypothallic film to extend far around the per-
fected fruit-mass. In well-matured aethalia the sporangium-like units
stand out distinctly, particularly above and around the margins.
Closely and compactly crowded, they become prismatic by mutual
pressure, and attain sometimes the height of a centimeter or more.
In the center of the fructification, next the hypothallus, these struc-
tures are very imperfectly differentiated. Many are here horizontally
placed, and perhaps supplied with an imperfectly formed peridium, — ■
if so may be interpreted the lowest parts of the capillitial structure,
the long, branching, ribbon-like strands which lie along the hypo-
thallus. Some of these branch repeatedly with flat anastomosing
branchlets, ultimately fraying out into lengthened threads, and re-
main after the superstructure has been blown away. From every
part of the structure so described, but more especially from the
margins, are given off in profusion the strange cystiferous threads, so
characteristic of this genus. These are exceedingly delicate filaments,
attached at one end, it may be, to a principal branch, at the other
free or united to a second which again joins a third, and so looping and
branching they form a more or less extended network, a capillitium
in which are entangled the myriad spores. Each filament bears at its
middle point (or is it the meeting-point of two?) a peculiar plexus

158 THE MYXOMYCETES

which embraces several large cysts or vesicles whose function or
homology is not clear.

From the base of the fructification rise also ascending branches
which are black, terete and not infrequently branched as if to form
the capillitium of a stemonitis. These ascending branches are in many
cases, probably in all, real, though as yet imperfectly developed, col-
umellae. They rise, at least in many cases, directly from the hypo-
thallus; each is central to one of the individual units referred to,
rising to about two-thirds its height, but never attaining the summit.
The columella bears cystiferous threads sparingly, if at all; never-
theless these abound in the intermediate portions of the capillitium,
and are especially noticeable beyond the level of the top of the colu-
mella. Many are so arranged that the plexus with its vesicles occupies
a place in the plane separating adjacent units, suggesting the possibil-
ity that we have here to do with an imperfectly developed surface net
and peridium. In this view the cysts would represent the meeting-
point of two opposite radial capillitial threads rather than the middle
of one. This accords with Rostafinski's observations and drawings.
The cysts, then, belong morphologically to the peridium or sporangium
wall. It is a stemonitis whose sporangia have never been perfectly
differentiated, a case of arrested development. See further under
Stemonitis confluens.

Dermodium inquinans Lk. ex Fr., Symb. Gast. 9, 1817, is cited by
Rostafinski as a probable synonym of this species, and distinct from
the species so named by Link, which is thought to be a synonym for
Amaurochate fuliginosa. Fries spells the generic name "Demordium."
Rostafinski really offers the first definitive description. Fries probably
distinguished it, but his description would not indicate the fact except
for the added note wherein appears the reason for discarding an ap-
parently older name given by Link. But neither Link nor Sowerby
distinguished by description or figure Brefeldia from Amaurochaete.

Throughout the northern forest, Maine to Vancouver Island, not
common, Argentina; also throughout Europe.

6. Stemonitis Gleditsch emend. Rost.

Versuch7. 1873.

1753. Stemonitis Gleditsch, Meth. Fung. 140, in part.

Sporangia distinct, though often closely aggregated, cylindric, stip-
itate; columella prominent; capillitium well developed by repeated
lateral and apical branching of the columella, at length assuming at

STEMONITIS 159

the surface the form of a distinct net which supports an evanescent
peridium.

The genus is marked by its surface net supported at the tips of the
dichotomously branched divisions of the columella. Over the net is
spread, theoretically at least, the peridial film supported at times by
very short points projecting from the net— the peridial processes;
the peridium, however, is seldom seen; in some cases perhaps never
developed. Rostafinski first defined the genus as employed by
recent writers. Gleditsch simply renamed Micheli's Clathroidastrum;
all writers up to the time of Rostafinski included species of other
genera.

The taxonomy of this genus is extremely difficult. Macroscopic,
defining characters are few, and even these sometimes uncertain.
Microscopic distinctions also tend to be illusive, variable in such fash-
ion that often at the critical point the most exact description fails.
All that may be done at present is to recognize two or three definite
types and then cautiously differentiate among these until more gen-
eral study of the group brings to service a wider range of observation.

Since spore characters seem to be reasonably constant, they are
largely stressed in the accompanying key. The surface is in some
species beautifully and plainly reticulate, in others, the reticulations,
while present, are very delicate, and an oil immersion lens is required
to distinguish them. In some species, notably S.fusca, the reticulations
are combined with warts at the angles. These are referred to as
verrucose-reticulate. Some are rather coarsely papillate, others nearly
smooth even under oil. The capillitium is more variable but is often
distinctive.

KEY TO THE SPECIES OF STEMONITIS

a. Spores reticulate or verrucose-reticulate b

a. Spores not reticulate; verrucose to smooth /

b. Sporangia connate below 1. S. trechispora

b. Sporangia distinct, appressed or scattered c

c. Spore-mass black; net developed mainly at base; 3-6 mm. tall 2. S. nigrescens

c. Spore-mass fuscous or paler <*

d. Dark fuscous; surface net rather coarse; 18-25 mm. tall 3. S. dictyospora
d. Fuscous; surface net fine-meshed; usually 6-10 mm. tall 4. S.fusca
d. Paler, with vinaceous tints, in small clusters; usually

under 6 mm. tall e

e. Benzo-brown; spores banded-reticulate; surface net often

incomplete ' 5. 5. virginiensis

e. Lilaceous brown; spores faintly and irregularly reticulate;

surface net developed below only 6. 5. hyperopia

f. Sporangia connate with plate-like processes at junctions

of capillitial branches of adjoining sporangia 7. S. confluens

f. Sporangia separate S

160 THE MYXOMYCETES

g. Spores in clusters of 4 or more 8. S. uvifera

g. Spores not in clusters h

h. Sporangia over 15 mm. tall, flexuous *

h. Sporangia under 15 mm. tall, subflexuous to erect j

i. Sporangia angular in section; columella more or less lateral 9. S. fenestrate

i. Sporangia terete; columella central 10. S. splendens

j. Peridial net with coarse meshes, 50-125 n across 11. 5. webberi

j. Meshes of peridial net mostly less than 50 y. k

k. Spores under 7 ax in diameter, nearly smooth /

k. Spores 7 \i in diameter or larger, verrucose m

I. Sporangia 7-15 mm. tall; ferruginous; spores 5-7 xx 12. S. axifera

I. Sporangia under 5 mm. tall; vinaceous; spores 4-5 xx. . . . 13. S. smithii

m. Purplish ferruginous; closely fasciculate; columella often

with plate-like expansions at tip 14. S. flavogenita

m. Sporangia in small, scattered clusters or gregarious; colu-
mella without plate-like expansions n

n. Slender, acuminate; columella dissipated below tip of

sporangium; 7-10 mm. tall 15. 5. carolinensis

n. Columella ending abruptly below obtuse tip of sporan-
gium, 3-7 mm. tall o

o. Peridial net close-meshed, scantily developed above; usually

on wood 16. S. pallida

o. Peridial net very fine, complete; usually on herbaceous

stems or leaves 17. 5. herbatica

1. Stemonitts trechispora Macbr.

N. A. Slime-Moulds ed. 2. 159. 1922.

1909. Stemonitis fusca Roth, var. trechispora Torrend, Fl. Myx. 141.

Sporangia irregular, small, fuscous black * to dull black, sessile or
nearly so, and more or less coalescent below, free above, 5-7 mm. tall;
columella black, tapering gradually to a point beneath the apex and
giving rise to a capillitium of few, irregular branches; peridial net open,
the meshes uniform in size, several times the spore-diameter; hypo-
thallus continuous, well developed; spores nearly black in mass, purple-
brown by transmitted light, strongly but irregularly reticulate with
20-30 or more meshes to the hemisphere, 10-12 /x in diameter. Plas-
modium unknown.

Stemonitis trechispora was originally named by Berkeley but this
name seems not to have been published (see Lister, ed. 3. 133). It is
usually entered as a variety of S. fusca, but the very large, reticulate
spores seem to be distinctive, and the color and structure are also dis-
tinct. A very abundant collection by Mr. Hagelstein, from Long Island,
approaches fusca in its separate sporangia, but otherwise seems to
belong here. Pending further information it seems best to maintain
the species.

On vegetable debris, Maine, Long Island, Washington, Venezuela.

STEMONITIS 161

Reported from England, Denmark, Rumania and other European
localities, also Malay Peninsula, Japan.

2. Stemonitis nigrescens Rex

Proc. Acad. Nat. Sc. Phila. 1891 : 392.
PI. XI, Fig. 246.

1909. Stemonitis fusca Roth, var. nigrescens Rex ex Torrend, Fl. Myx. 141.

Sporangia gregarious in small, loose clusters upon a common hy-
pothallus, erect, cylindric, stipitate, 3-5 mm. tall, fuscous black *
becoming fuscous when blown; stem black, extremely short, about
0.5 mm. ; columella reaching the apex, violet-black, darker near the
surface; peridial net developed chiefly at the base, elsewhere incom-
plete or lacking; spores black in mass, violet-brown by transmitted
light, verrucose-reticulate as in S. fusca, but with reticulations less
marked, 8-9 n in diameter.

The author of this species remarks: "This species is noteworthy for
its comparatively short stipes, its very spinulose spores, and its black
or nearly black color, the slight violet tint being only apparent on close
inspection, especially in fresh moist specimens."

It is a small but very beautiful form, at first sight to be mistaken for
a short S. fusca, though much more intensely black before the spores
are shed. The capillitium is concolorous, the inner network of rather
few open meshes, the outer of large hexagonal openings, the arcuate
threads of which are remarkable for the size, and especially the number,
of the peridial processes, as many as five or six sometimes appearing
along one side of a single mesh. The stipe is very short, and the colu-
mella runs as a straight, gradually diminishing axis to the very apex
of the sporangium. Total height 3-5 mm.

Lister follows Torrend in regarding this as a variety of S. fusca but it
seems distinct in size, habit and color.

Not common. Pennsylvania, Virginia, North Carolina, Indiana,
Iowa, Arizona, Oregon, California; Wales.

3. Stemonitis dictyospora Rost.

Mon. 195. 1875.
PI. XI, Figs. 247, 248.

1893. Stemonitis castillensis Macbr., Bull. Nat. Hist. S. U. Iowa 2 : 381.

Sporangia slender, rigid, erect, 18-25 mm. tall, in large clusters,
4-8 cm. across, dark fuscous; columella prominent, reaching nearly to
the apex, abundantly branched, the branches forming an intricate dark

162 THE MYXOMYCETES

capillitium; surface net large-meshed, the meshes several times the
diameter of the spores; spores clear violet, strongly reticulate, 7-8 /*.

Obviously close to S. fusca, but distinguished by its unusual size,
somewhat darker color, more robust capillitium, larger meshes of the
net and more strongly reticulate spores.

A specimen sent by Massee to Wingate, said to have been named by
Rostafinski, is certainly S. fusca, thus bearing out the comment in the
Lister monograph. If S. dictyospora Rost. is not applicable to our large
specimens they must some day be given a new name.

Collections from Moldavia, reported by Brandza (1929) as S. fusca
and described as 2 cm. in height, may well belong here.

Oregon, Nicaragua; Europe.

4. Stemonitis fusca Roth

Roem. Mag. Bot. 2 : 26. 1787.
PL XI, Figs. 249, 250.

1792. Trichia nuda With., Br. PL ed. 2. 3 : 477.

1796. Stemonitis fasciculata Pers., Obs. Myc. 56, non 1791.

Sporangia slender, cylindrical, occurring in tufts, usually 6-8 mm.
tall, occasionally larger; fuscous * varying occasionally to benzo-
brown * or hair-brown * and tending to become pallid as the spores are
disseminated; stem black, shining, usually about one-fourth the total
height but varying to one-half; columella prominent, mostly attaining
the apex, branching freely ; capillitium of slender dusky threads which
anastomose freely to form a dense interior network; peridial net close-
meshed; hypothallus scanty but distinct, membranous, common to all
sporangia of a cluster; spores fuscous * in mass, pale violet by trans-
mitted light, covered with blunt spines or warts connected by delicate
reticulate ridges, 7.5-10/* in diameter. Plasmodium white, passing
through blue to black.

The English monograph recognizes no less than five varieties in
addition to the typical form. Of these five, nigrescens and trechispora
are here regarded as distinct species; rufescens List, has verrucose-
reticulate spores 5-8 /x; flaccida List, has weak sporangia with imper-
fect surface net, and confluens List, is described as approaching Amau-
rochaste.

As here defined, the spores, the characteristic color, the moderate
size and the typical growth habit are the distinctive features of the
species. The spores possess blunt spines connected by reticulations
which may be resolved into lines of minute warts. Forms with faintly
spinulose or nearly smooth spores are excluded.

On rotten wood and occasionally on other substrata. Widely dis-

STEMONITIS 163

tributed in north temperate and tropical regions to Brazil and South
Africa.

5. Stemonitis virginiensis Rex

Proc. Acad. Nat. Sc. Phila. 1891 : 391.
PL XI, Figs. 251, 252.

Sporangia cylindric or elongate-ovate, gregarious in small clusters,
benzo-brown * to drab*, 1.5 to 6 mm. tall, sometimes more; stem
black, shining, 0.5-2 mm.; columella reaching apex, giving rise to a
delicate capillitium ; meshes of peridial net small, scarcely greater than
diameter of spores; hypothallus common to the cluster; spores umber-
brown in mass, pale lilac-brown by transmitted light, finely banded-
reticulate, the reticulation often incomplete, 6-8 /x in diameter. Plas-
modium unknown.

Distinguished from S. fusca by the small, slender, acuminate, vina-
ceous sporangia growing erect in small tufts and by the slightly smaller
and banded spores.

On dead wood: Virginia, Iowa, Oregon, California; central and
southwestern Europe.

6. Stemonitis hyperopia Meylan

Bull. Soc. Vaud. Sc. Nat. 52 : 97. 1918.
PL XI, Figs. 253, 254.

1893. Comatricha typhina (Pers.) Rost. var. heterospora Rex, Proc. Ac. Nat. Sc.
Phila. 367. '

Sporangia in small, loose clusters, broadly cylindrical or somewhat
ovate, lilaceous brown, 2-3.5 mm. tall; stalk short, continued into the
slender columella; capillitium a close network of rather fine threads,
coalescing to form a delicate surface net over the lower half or two-
thirds of the sporangial surface; spores pale filaceous, the surface
covered by a faint, irregular reticulation with a few scattered warts,
5-6 ix. Plasmodium watery white.

The English monograph includes here as var. micros por a Lister a
form with spores 3.5-4 /z, synonymous with Comatricha typhoides var.
microspora Lister 1894, and C. microspora Lister 1919.

The reticulations are exceedingly delicate, scarcely to be distin-
guished without the aid of an oil immersion objective.

The species is not commonly found in collections, but is probably
not uncommon, probably ordinarily determined as C. typhoides, of

164 THE MYXOMYCETES

which Rex regarded it as a variety. The constant, even though usually
incomplete surface net seems to warrant its place in Stemonitis.
Material distributed by Morgan as Comatricha pumila (apparently not
published) clearly belongs here.

Eastern United States, Washington, Puerto Rico, Chile; Europe,
Japan.

7. Stemonitis confluens Cooke & Ellis

Grev. 5:51. 1876.
PL XI, Figs. 255, 256.

1894. Stemonitis splendens Rost. var. confluens Lister, Mycet. 112.

Sporangia fasciculate, dark fuscous, in close-set tufts on a persistent
hypothallus; sporangia separated at tips and usually at bases, else-
where confluent; total height 2-3 mm.; stipe short, sometimes indis-
tinct or wanting, merging into the dark columella which in turn gives
rise to a prolific membranously-angled capillitium, merging at bound-
aries into a large-meshed surface net; peridium fugacious, except where
capillitial branches of neighboring sporangia are joined, where it
persists as a disk-shaped membrane about equal to a surface mesh;
spores blackish in mass, purplish brown by transmitted light, minutely
spinulose, 12-14 fx in diameter. Plasmodium white.

Represented in the S. U. I. herbarium only by specimens collected
by Ellis in New Jersey. In the Lister monograph the species is reported
from New England and North Carolina, as well as from the British
Isles, France and Germany. The description as there given makes it
doubtful whether the species so reported is the same as our material.
Meylan reports it from the Alps.

8. Stemonitis uvifera Macbr.

N. A. Slime-Moulds ed. 2. 161. 1922.
PL XI, Figs. 257, 258, 259.

Sporangia slender, cylindrical, tufted in medium sized clusters as in
S. fusca, the individual sporangia more or less recumbent, fuscous*,
7-9 mm. high; stipe black, polished, one-fourth to one-third the total
height; columella not reaching sporangial tip, marked by obscure
spirals; capillitium of stout branches, often membranously flattened
at angles; peridial net with large irregular meshes and many free ends;
hypothallus distinct, common to all sporangia; spores nearly black in
mass, pale sooty brown by transmitted light, somewhat flattened and
often irregular in shape, distinctly verruculose over three-fourths of the

STEMONITIS 165

surface, the rest smooth, mostly 8-10 /x in diameter, but many larger,
clustered in groups of four or more, rarely single.

The clustered spores and the loose surface net are the outstanding
characteristics of this species. Miss Lister speaks of a cap of minute
spines on the exposed side of the spores. This is scarcely adequate, as
the illustrations will show.

Rare. District of Columbia, Pennsylvania, Montana, Washington.

9. Stemonitis fenestrata Macbr.

N. A. Slime-Moulds ed. 2. 166. 1922.
PL XI, Figs. 260, 261.

1890. Stemonitis bauerlinii Mass. f. fenestrata Rex, Proc. Ac. Nat. Sc. Phila.
1890 : 37.

Sporangia aggregated, in tufts 2 cm. or more in diameter, rich
purple-brown, on a common hypothallus, more or less erect, stipitate,
15-22 mm. tall, slender, triangular in section; stipe black, about one-
third the total height, passing into a slender columella which is lateral
in position, not central, but little branched, continued almost to the
apex; the capillitium consisting almost entirely of the peripheral net,
which presents meshes of unusual uniformity of size and shape;
spores dark in mass, pale brownish by transmitted light, spherical or
slightly elongated, 7-8.5 /a. Plasmodium probably white.

The remarkable shape of the sporangium and the peculiar regularity
of the surface net, the lateral columella, all combine here to warrant
the erection of a distinct species. Doctor Rex referred this to S. bauer-
linii Mass. At that time he had not the author's description, and had
seen only a very poor fragment received with notes in a letter.
Mr. Massee's description makes it immediately evident that what-
ever other affiliations S. bauerlinii may have, by description it has at
least none with 5. fenestrata. Massee's species is described as having
the "mass of spores black," the capillitium with branches springing
from the columella, the main branches more and more numerous,
thicker, and irregular towards the apex of the sporangium, and often
forming irregular, flattened expansions. This suggests some form
of S. dictyospora Rost. Possibly for such reasons Lister referred it to
5. splendens Rost., which was undoubtedly regarded by the author
as belonging to the fusca group.

The long, slender, simple columella is not only lateral, but occupies
the sharp vertical angle of the triangular, prismatic sporangium.
Furthermore, the sporangium is at maturity strangely twisted, so that
the columella in its ascent accomplishes one or more spiral turns. In
forms collected by Dr. Rex, which seemed to him most nearly to

166 THE MYXOMYCETES

agree with Massee's species, the inner capillitium is somewhat abun-
dant, but the character of the columella just the same.

On rotten wood, eastern United States and Ontario to Colorado;
India.

10. Stemonitis splendens Rost.

Mon. 195. 1875.
PI. XI, Figs. 262, 263.

1880. Stemonitis morgani Peck, Bot. Gazette 5 : 33.

1892. Stemonitis maxima Schw. ex Massee, Mon. 74.

1892. Stemonitis acuminata Mass., Mon. 78.

1892. Stemonitis bauerlinii Mass., Mon. 79.

Sporangia long-cylindrical, flexuous, clustered irregularly, some-
times forming patches 6-10 cm. or more in extent, natal-brown *,
14-23 mm. tall; stem black, polished, enlarged below; columella
black, sparingly branched; capillitium open, of brown, sparingly
branched threads, bearing a surface net of moderately small, rather
uniform meshes mostly under 50 fx in diameter; peridial processes few,
inconspicuous; hypothallus thin but well developed, silvery, common
to all the sporangia of a cluster; spores lilaceous brown by transmitted
light, verrucose, 8 n in diameter. Plasmodium white on maple, creamy
on linden.

According to Lister, S. maxima Schw. is a synonym of S. fusca.
Mr. Bilgram, who has examined what is left of Schweinitz' type in
Philadelphia, believes it represents the present species, as did Massee,
and most of the material distributed as S. maxima is the present
species. Pending further study it seems wise to retain Rostafinski's
name.

The var. jiaccida Lister seems little more than a growth form in
which the sporangia are weak and adherent due to unfavorable weather
conditions during development.

On rotten wood, in the United States especially on Acer saccharinum,
not uncommonly on linden and willow, occasionally on ash. Widely
distributed in temperate and tropical regions.

11. Stemonitis webberi Rex

Proc. Acad. Nat. Sc. Phila. 1891 : 390.
PI. XI, Figs. 264, 265.

1894. Stemonitis splendens Rost. var. webberi Lister, Mycetozoa 112.

Sporangia cylindric with obtuse apex, clustered in small tufts up to
1 cm. broad, sometimes larger, natal-brown * to bone-brown *, usually

STEMONITIS 167

8-10 mm. tall but occasionally varying from 5-15 mm.; stem jet-
black, shining, usually expanded at base into a broad disk with con-
spicuous rhizoidal outgrowths; columella dark, tapering upward, and
becoming dissipated just below tip; capillitium open, peridial net
pale, with many large, irregular meshes 50-125 fx wide; hypothallus
continuous, well developed, thin, transparent, or thicker and then
silvery; spores bone-brown * in mass, yellowish brown or lilaceous
brown by transmitted light, minutely verruculose, 8-9 /j, in diameter.

The capillitium often possesses numerous membranous expansions
near the stipe, as in the type. Distinguished from 5. splendens by the
smaller size, erect habit, pale large-meshed surface net, more ferrugi-
nous cast. European authors generally regard this as merely a form of
S. splendens with large irregular meshes. Brandza (1929) reports it as
exceeding 5 cm. in height.

On dead wood, temperate North America, chiefly west of the
Mississippi, Cuba. Also reported from Europe, south and west Africa,
Manchuria and Japan.

12. Stemonitis axifera (Bull.) Macbr.

N. A. Slime-Moulds ed. 2. 168. 1922.
PI. XI, Figs. 266, 267.

1791. Trichia axifera Bull., Champ. 118. pi. 477, fig. 1.
1818. Stemonitis ferruginea Ehr., Sylv. Myc. Berol. 25.
1829. Stemonitis ferruginea Ehr. ex Fr., Syst. Myc. 3 : 158, in part.
1894. Stemonitis microspore, List., in Morgan, Jour. Cin. Soc. Nat. Hist.
16 : 138.

Sporangia cylindrical with acuminate apex, fasciculate in small,
dense clusters, wood-brown* to avellaneous *, 7-15 mm. tall; stem
black, shining, }i to % total height; columella branching evenly,
dissipated before reaching the tip, branches clear brown, dividing and
anastomosing and at the surface uniting to form a fine-meshed peridial
net; hypothallus membranous, common to a cluster; spores pallid,
faintly ferruginous, spherical or somewhat oval or irregular, nearly
smooth, or, under oil immersion, faintly roughened or spinulose, 5-7 /x.
Plasmodium white.

This is S. ferruginea Ehr., under which name both it and S . jlavogenita
Jahn are commonly distributed. Bulliard's reference to the white
color of the early stages would seem to be distinctive. Fries includes
both Bulliard's small-spored form with white plasmodium and a
larger-spored form with yellow plasmodium under Ehrenberg's name.

Distribution world-wide; common.

168 THE MYXOMYCETES

13. Stemonitis smithii Macbr.

Bull. Nat. Hist. Iowa 2 : 381. 1893.
PI. XII, Figs. 268, 269.

1911. Stemonitis Jerruginea Ehr. var. smithii Lister, Mycetozoa ed. 2. 150.

Sporangia subcylindric, larger in center, tapering to base and tip,
erect, not spreading, occurring in small, close-packed clusters; light
cinnamon-drab * to vinaceous fawn *, 2.5-5 mm. in height; stem jet-
black, shining, about % of total height; columella dark, becoming
brown at tip, gradually tapering and dissolving into capillitium some
distance below apex; capillitium light brown, of abundant, sparingly
united branches of uniform thickness; peridial net delicate, of small,
regular, polygonal meshes with few peridial processes; hypothallus
thin but distinct, common to each cluster; spores pale, almost color-
less by transmitted light, nearly smooth, but in most cases sparsely
and minutely warted when viewed under oil immersion; spherical or
slightly irregular, 4-5 fx in diameter. Plasmodium greenish yellow to
reddish purple.

Originally described from Nicaragua, whence we have several col-
lections made by Mr. C. L. Smith and Professor Shimek. Widely dis-
tributed in the United States but apparently not common. Miss Lister
reports it as a variety of S. Jerruginea ( = S. axifera) from a number
of old-world localities. It is also reported from Japan.

14. Stemonitis flavogenita Jahn

Abh. Bot. Ver. Brandenb. 45 : 165. 1904.
PI. XII, Figs. 270, 271.

1829. Stemonitis Jerruginea Ehr. ex Fr., Syst. Myc. 3 : 158, in part.

1899. Stemonitis axifera (Bull.) Macbr., N. A. Slime-Moulds 120, in part.

Sporangia cylindrical, obtuse, closely fasciculate, wood-brown * at
first, becoming natal-brown * when blown, usually 4-8 mm. tall,
sometimes 12 mm.; stipe short, black, passing into a columella which
usually ceases abruptly below the apex, often with plate-like prolifera-
tions; capillitium a loose network with many broad expansions; peridial
net delicate, the meshes small but uneven, 6-15 ju or larger, with many
projecting points; hypothallus common to a cluster; spores lilaceous
brown by transmitted light, verruculose, 7-10 fx. Plasmodium yellow,
or occasionally pallid or white.

Distinguished from 6". axifera, with which it has often been confused,
by the usually yellow plasmodium, the larger, more distinctly marked
spores, the darker and more vinaceous color and often by the proliferate
tip of the capillitium. Apparently less common in the United States

STEMONITIS 169

than S. axifera but widely distributed, appearing mainly on dead
wood.

New England and Pennsylvania to Washington and California;
Europe, Java.

15. Stemonitis carolinensis Macbr.

N. A. Slime-Moulds 122. 1899.
PI. XII, Figs. 272, 273.

1894. Stemonitis tenerrima Curtis ex Morgan, Jour. Cin. Soc. Nat. Hist.

16 : 137, non Curtis.
1911. Stemonitis pallida Wingate ex Lister, Mycetozoa ed. 2. 149, in part.

Sporangia tufted in scattered clusters, small, slender, cylindric but
tapering from the apex, at first brownish drab *, then ashen or purplish,
stipitate, 7-10 mm. tall; the stipe usually short, black and shining,
even; hypothallus well developed, black or very dark brown; columella
black, gradually diminishing, at length dissipated some distance below
the clavate or acuminate apex of the sporangium; capillitium dense,
the inner of many scarcely expanded, pallid, freely anastomosing
branches, the outer a net of very small meshes, often less than the
spores, 3-15 yu, peridial processes imperceptible; spore-mass vinaceous,
spores by transmitted light pale violaceous brown, very minutely
roughened, 6.5-7.5 ix.

Very closely related to 5. pallida and S. herbatica, but recognizable
by its proportionately much more slender, taller, acuminate sporangia,
paler and denser capillitium and the remarkably close-meshed net.

Not uncommon south: Virginia, North Carolina, Kentucky, Ala-
bama, Puerto Rico; Congo.

16. Stemonitis pallida Wingate

in Macbr., N. A. Slime-Moulds 123. 1899.
PI. XII, Figs. 274, 275.

Sporangia gregarious or somewhat clustered, erect, cylindric, obtuse,
4-6 mm. tall, blackish dusky drab and then ferruginous, becoming
pallid, stipitate; stipe short, black, polished, rising from a thin, brown
or iridescent hypothallus; columella percurrent, ceasing abruptly at
the apex; capillitium filling the interior with abundant branches which
form at the surface a close-meshed net, little developed above, making
the apex very blunt; spores in mass dark brown, by transmitted light
dusky, nearly smooth, 7-8 fx.

This species is well recognized at sight, among the fuscous forms, by
its scattered, erect habit. In color it is not unlike S. fusca, but has an
added reddish tinge. In form it is peculiar by virtue of the blunt

170 THE MYXOMYCETES

rounded apex, which seems to be a constant character. The spores
under a high power lens appear almost smooth; under oil immersion
they present very delicate, low, scattered papillae.

Not common; eastern United States to Iowa, Washington, Oregon;
Rumania, Poland, Malay Peninsula, Japan.

17. Stemonitis herbatica Pk.

Rept. N. Y. State Mus. 26 : 75. 1874.
PL XII, Figs. 276, 277.

1899. Stemonitis axifera (Bull.) Macbr., N. A. Slime-Moulds 120, in part.

Sporangia clustered, in scattered tufts, cylindric, obtuse, stipitate
or sometimes nearly sessile, natal-brown* or army-brown* fading to
avellaneous, 3-7 mm. tall; stipe fuscous or jet-black, only slightly
expanded below, short; hypothallus scanty or none; columella lessen-
ing upward, sometimes attaining the apex of the sporangium, some-
times dissolved in capillitial threads some distance below; capillitium
of rich brown threads forming the usual inner network of medium
density, with many wide expanded nodes, the surface net made up of
delicate, almost colorless threads surrounding small polygonal meshes;
spore-mass ferruginous; spores by transmitted light very pale, brown-
ish, minutely warted, 7-9 /jl. Plasmodium white to pale yellow.

The low tufts of brown sporangia with short black stipes, borne
often as Dr. Peck found them, assembled on living leaves, dis-
tinguish this little species. Probably widely distributed, but confused
with short forms of other species; sometimes also on rotten wood or
debris.

New York, Iowa, Washington, Oregon; Europe, Asia, Africa.

6. Comatricha Preuss emend. Rost.

Vers. 7. 1873.
1851. Comatricha Preuss, Linnaga 24 : 140, in part.

Sporangia cylindric or globose, usually stipitate; stipe prolonged
upward to form a more or less extended and tapering columella bearing
branches on every side, which by repeated divisions and reunions form
the capillitium; ultimate branch- tips free, not supporting a surface
net parallel to the peridial wall; peridium evanescent, perhaps some-
times not developed at all.

The genus Comatricha was set off from Stemonitis by the joint
efforts of Preuss and Rostafinski. Preuss included in his genus Coma-
tricha alien forms, and besides failed to give an accurate definition;

COMATRICHA 171

he included, however, in his list some species which have since been
known by his generic name.

The distinction between the two genera is admittedly somewhat
artificial, and species are sometimes arbitrarily assigned to one genus
or the other. The diagnosis in any case turns upon the presence or
absence of a surface net. In Stemonitis this is formed by the anasto-
mosing of the ultimate divisions of the capillitial branches. In Coma-
tricha the anastomosing is general, from the columella out, and is not
specialized at the surface. Attempts to reunite the two genera seem
to result in no apparent advantage. They come very near together,
but their separation as suggested by Rostafinski remains convenient.

KEY TO THE SPECIES OF COMATRICHA

o. Peridium iridescent, persistent, at least at the base; stipe

very short or lacking b

a. Peridium fugacious; stipe distinct d

b. Sessile or short-stipitate; clavate-truncate; spores

roughly warted 1 . C. caspitosa

b. Sessile; cylindrical; spores reticulate c

c. Black; peridium more or less persistent over entire sur-
face; spores 10-12 /z 2. C. cylindrica

c. Brown; peridium persistent only at base; spores 8-9 ju. . . . 3. C. rispaudii

d. Sporangia densely clustered jcapillitium scantily branched e

d. Sporangia gregarious or scattered; capillitium various g

e. Ferruginous, 5-10 mm. tall 4. C. flaccida

e. Dark brown or blackish /

/. Sporangia 10-25 mm. tall; spores roughly warted or

reticulate 5. C. longa

f. Sporangia 3-6 mm. tall; spores echinulate 6. C. irregularis

g. Spores black or dark purplish in mass; violet-brown by

transmitted light h

g. Spores lilaceous or ferruginous in mass; pallid by trans-
mitted light u

h. Capillitium simple, with few or no anastomoses i

h. Capillitium intricate I

i. Capillitium caducous, falling away with the spiny spores . . 7. C . filamentosa

i. Capillitium persistent, at least above; spores minutely

warted or nearly smooth j

j. Capillitium moderately dense, but with few anastomoses;

columella nearly reaching the summit 8. C. laxa

j. Capillitium looser; columella shorter k

k. Very minute, usually under 0.5 mm. tall; columella not ex-
ceeding middle of sporangium; capillitium forking repeatedly 9. C. cornea

k. Minute, 0.7-1.5 mm. tall; columella very short; capillitium
of slender, simple or sparsely branched threads with ex-
panded tips 10. C. fimbriata

I. Spores mostly over 10 n m

I. Spores mostly under 10 p. n

172 THE MYXOMYCETES

m. Robust, truncate, 2-6 mm. tall; stem equal to sporangium

or shorter 11. C. suksdorfii

m. Cylindrical or slightly ovate, 7-8 mm. tall; stipe at least

half the total height 12. C. pacifica

n. Spores reticulate 13. C. reticulata

n. Spores warted to nearly smooth o

o. Capillitium caducous except at top ; spores usually under 6 n 14. C. fragilis

o. Capillitium persistent; spores usually larger p

p. Sporangia distinctly cylindrical q

p. Sporangia globose to ovoid, rarely short cylindrical r

q. Stipe long, equal to sporangium; spores 7.5-8 fi 15. C. cequalis

q. Stipe short; spores 9-10 p. 16. C. subcoespitosa

r. Usually 2-4 mm. tall 17. C. nigra

r. Under 2 mm. tall •s

s. Columella nearly reaching apex 18. C. ellisii

s. Columella shorter t

t. Columella reaching middle of sporangium; spores

coarsely warted 19. C. lurida

t. Columella divided at base into several main branches;

spores finely spinulose 20. C. elegans

u. Cylindrical; spores with sparsely scattered clusters of warts 21. C. typhoides

u. Spores more densely and uniformly spinulose v

v. Base of peridium persisting as a cup; globose or elliptical 22. C. rubens
v. Base of peridium not persistent; ovate to short cylin-
drical w

w. Capillitium pallid or flesh colored 23. C. lenerrima

w. Capillitium dark 24. C. pulchella

1. COMATRICHA C^SPITOSA StUTgis

Bot. Gazette 18 : 186. 1893.
PI. XII, Figs. 278, 279.

1907. Diachcea ccespitosa (Sturgis) List., Jour. Bot. 45 : 186.

Sporangia densely crowded or caespitose, sessile or short-stipitate,
clavate, 1-1.5 mm. high; peridium gray, iridescent with blue tints,
comparatively permanent but finally disappearing; columella attain-
ing two-thirds to three-fourths the height of the sporangium, giving
rise throughout its length to the dense blackish capillitium; hypo-
thallus delicate, inconspicuous; capillitium, the main branches thick at
the point of origin, frequently anastomosing, and becoming gradually
thinner toward the surface of the sporangium, the tips pointed, free,
forming the network; spores blackish violet in mass, by transmitted
light pale brownish violet, irregularly verrucose, 10-13 ;u.

A very distinct and curious species. The sporangia are densely
crowded, though by the nature of habitat somewhat tufted. The
shape of the individual sporangium is quite uniformly clavate or

COMATRICHA 173

obovate, decidedly truncate above. The spores are rather variable in
size, the warts also of different sizes and more or less clustered.

This species, as indicated, was described by its author as a coma-
tricha. To transfer it to another genus seems idle, especially when
long-established generic boundaries must be seriously disturbed ex-
pressly to admit the new arrival.

New England, North Carolina, on moss and lichens.

2. Comatricha cylindrica (Bilgram) Macbr.

N. A. Slime-Moulds ed. 2. 173. 1922.
PI. XII, Figs. 280, 281.

1905. Diachcea cylindrica Bilg., Proc. Ac. Nat. Sc. Phila. 524.

Sporangia cylindrical with obtuse apex, sessile, gregarious, iridescent,
steel-gray or bronze, 1-1.7 mm. high, 0.5-0.65 mm. thick; hypothallus
whitish, rugose; sporangium wall membranous, hyaline, not adhering
to the capillitium; columella arising from the hypothallus and extend-
ing nearly to the apex, brown, very light and semi-translucent near
the base, irregular, rlexuous, limeless throughout; capillitium brown,
radiating from the columella to the periphery, repeatedly branching
and anastomosing; spores warted, the warts connected by ridges form-
ing a more or less perfect, coarse reticulation, violaceous, pale, 10-12 n-

This is a very interesting species, closely related to the preceding,
from which it differs chiefly in the reticulation and generally more
uniform character of the spores. The author hesitated about the
generic reference, finally referring it to Diachea despite the lack of
calcium, because it was sessile and had a peridium rather more per-
sistent than is usual in comatrichas. But the presence of lime in stipe
and columella is an essential element in the diagnosis of Diachea,
while length of stem is everywhere variable in stipitate forms of every
genus, and the persistence of the peridium is also an uncertain factor.

Pennsylvania, New Hampshire.

3. Comatricha rispaudii Eagelstein

Mycologia 21 : 297. 1929.
PL XII, Figs. 282, 283.

Sporangia sessile, cylindrical or clavate-cylindrical, clustered in
dense groups up to thirty or more sporangia, sometimes superimposed,
color brown with a violet tinge, size 0.8-1.5 mm. high, 0.4-0.6 mm.
thick; sporangium wall evanescent but persisting at the base and
frequently forming pseudo-cups which blend with the hypothallus;
columella dark brown, stout at the base but becoming slender, solid,

174 THE MYXOMYCETES

sinuose and irregular, either extending to the apex or merging with
the capillitium; the latter consists of branched and anastomosing
brown threads spreading from all parts of the columella and generally
coarsely meshed within; spores pale violet-brown, 8-9 n in diameter,
reticulated with narrow ridges 0.5 fx high.
Long Island, N. Y., on dead leaves.

4. Comatricha flaccida (Lister) Morgan

Jour. Cin. Soc. Nat. Hist. 16 : 133. 1894.
PL XII, Figs. 284, 285.

1894. Stemonitis splendens Rost. var. flaccida Lister, Mycetozoa 112.

Sporangia semi-erect, closely crowded in tufts up to 5 cm. in di-
ameter, ferruginous, from a dark brown hypothallus, sessile or short-
stipitate; columella weak, crooked, percurrent, generally enlarged
irregularly at the apex; capillitium of few, slender, brown branches
which anastomose sparsely and irregularly as in C. irregularis, and
present when freed from spores the same chenille-like appearance;
spore-mass ferruginous brown; spores by transmitted light bright
reddish brown, minutely warted, 7.5-8 \i.

" Growing on old wood and bark of oak, willow, etc. The component
sporangia 5-10 mm. in length. The early appearance is much like
that of a species of Stemonitis, but the mature stage is a great mass of
spores with scanty capillitium, as in Reticularia; the columellas, how-
ever, are genuine and not adjacent portions of wall grown together."
Morgan.

Morgan's herbarium material is at hand for study. It meets his
description, needless to say, very generally. In what remains of the
type the membranous connections are obscure; in fact the relation of
such peridial fragments to the capillitium in any way is no longer
evident. But in any event the colony does not impress one as something
prematurely or improperly developed, a stemonitis gone begging; —
nothing of the kind; it is clearly a comatricha, easily identifiable as
such, with no trace of a surface net, but with long free tips in
plenty.

Misled, no doubt, by the peridial fragments referred to, Mr. Lister,
in the Mycetozoa, associated this with S. confluens Cke. & Ell., but
entered it as a variety of S. splendens Rost. just the same. In the
later editions of the same work, Ellis' species is set out, but Morgan's
retains the old position. In the light of present knowledge, the rela-
tionship suggested would be difficult of proof. If C. flaccida Morgan
be related to the splendens group at all, it must be with the form

COMATRICHA 175

known as S. webberi Rex, but it differs from this in almost every
particular. It has no net with meshes uniform or diverse; it is clear
brown in color, with a tinge of red, beneath the lens; the spores are
smaller, distinctly warted and with the reddish tinge of the capillitium;
in short, it seems to be a comatricha and not a stemonitis.

Specimens from western Washington differ in some particulars but
are apparently the same thing.

Ohio, Kentucky, Wisconsin, Montana, Washington, California; not
common. Reported from Europe and temperate regions generally.

5. Comatricha longa Peck

Rept. N. Y. State Mus. 43 : 24. 1890.
PI. XIII, Figs. 303, 304.

1892. Stemonitis longa (Pk.) Massee, Mon. 83.

1909. Stemonitis equinoctialis Welw., in Torrend, Fl. Myx. 138.

Sporangia crowded in depressed masses or tufts, black, stipitate,
cylindric, even, 10-25 mm. or more in height; stipe black, shining,
generally very short; hypothallus well developed, dark, shining; col-
umella black, slender, weak, generally dissipated some distance below
the apex; capillitium of slender brown or dusky threads anastomosing
to form an open network next the columella, but extended outwardly
in form of long free slender branchlets, now and then dichotomously
forked; spore-mass blue-black; spores by transmitted light dark brown,
globose, spinulose, sometimes reticulate, 8-10 /*.

A very remarkable species. Rare in the west, more common, as it
appears, in the eastern states. The sporangia occur in tufts about
1 or 2 cm. wide, springing generally from crevices in the bark of
decaying logs, especially willow and elm, in swampy places. The
sporangia are remarkable for their great length. Generally about
20-25 mm., specimens occasionally reach 50 mm.! The capillitial
branches are so remote that the spores are scarcely retained by the
capillitium at all.

New York, Pennsylvania, District of Columbia, Ohio, Wisconsin,
Iowa, Puerto Rico, Bolivia, Argentina; Europe, Africa, southern Asia,
Japan.

6. Comatricha irregularis Rex

Proc. Acad. Nat. Sc. Phila. 1891 : 393.
PL XII, Figs. 286, 287.

1893. Comatricha crypta (Schw.) Macbr., Bull. Lab. Nat. Hist. Iowa 2 : 139.

1894. Comatricha longa Pk. var. irregularis Lister, Mycetozoa 120.

Sporangia crowded in flocculent tufts, dark brown or black, semi-
erect or drooping, 3-6 mm. in height, irregularly cylindric, variable,

176 THE MYXOMYCETES

stipitate; stipe black, distinct, often one-half the total height; hypo-
thallus well developed, brown, shining; columella central, slender,
flexuous, reaching the apex, where it blends, by branching, with the
capillitium; capillitium loose, open, composed of arcuate threads which
radiate from the columella, and are joined together, forming a central,
irregular reticulation of large meshes, brown, paler toward the surface,
where the free ends are sometimes colorless; spore-mass black; spores
by transmitted light brown, echinulate, 7.5-9.5 ju.

Related, no doubt, to C. longa, but differing in habit, stature, as
in texture and structure of the capillitium. In C. longa the inner net
is extremely simple, a row or two of meshes at most, and the radiat-
ing branches are long and straight; in the species before us the
inner network is well developed, and the radiating branches propor-
tionately shorter and abundantly branching, with pale or white free
tips.

This species has been widely distributed as C. crypta based on
Stemonitis crypta Schw. (Trans. Am. Phil. Soc. II. 4 : 260, 1832.)
The type of Schweinitz' species is lost and the description is not clear,
hence the name should be discarded.

Generally, though not always, found growing in the crevices of the
bark on fallen logs of various deciduous trees. Not common.

New England west to the Cascade Mountains, south to Kansas
and Texas, Puerto Rico.

7. Comatricha pilamentosa Meylan

Bull. Soc. Vaud. Sc. Nat. 53 : 456. 1920.

1911. Comatricha nigra (Pers.) Schroet. var. alia Lister, Mycetozoa ed. 2. 152,
in part.

Sporangia dark brown, in large clusters, elliptical or subglobose,
0.8-1 mm. tall, borne on stems 0.5-1 mm. long; columella reaching to
summit, where it is sometimes slightly enlarged as in Enerthenema;
capillitium in the form of an interrupted net of anastomosing, sparsely
branched, smooth, brown filaments of uniform size, very weakly at-
tached to the stipe and falling away with the spores at maturity;
spores brown, spiny, 10-12 fx.

Regarded by Lister as a phase of Comatricha nigra var. alta. Meylan
considers it related to C. laxa. The caducous capillitium separates it
from the former species; the spore-size from both.

Switzerland.

COMATRICHA 177

8. COMATRICHA LAXA Rost.

Mon. 201. 1875.
PI. XII, Figs. 288, 289, 290.

1877. Lamproderma ellisiana Cooke, Ann. Lye. Nat. Hist. N. Y. 11 : 397.

1884. Comatricha macrosperma Racib., Rozpr. Akad. Krak. 12 : 76.

1891. Comatricha ellisiana (Cke.) Ell. & Ev., N. A. Fungi No. 2696.

1892. Comatricha sommerfeltii Blytt, Bidr. K. Norg. Sop. 3 : 8.
1892. Stemonitis laxa (Rost.) Massee, Mon. 79.

Sporangia scattered, gregarious, subglobose or short-cylindric and
obtuse, dusky, stipitate, 1-2.5 mm. tall; stipe short, black, tapering
rapidly upward from an expanded base; hypothallus scant or none;
columella erect, rigid, sometimes reaching nearly to the apex of the
sporangium, sometimes dichotomously branched a little below the
summit before blending into the common capillitium; capillitium lax,
of slender, horizontal branches, anastomosing at infrequent intervals
and ending in short, free tips; spores purplish brown, minutely warted,

7-11 m-

A minute, delicate little species; the stipe half the total height. In
general appearance the shorter forms resemble C. nigra, but are dis-
tinguished by a shorter stipe and more open capillitium. The sporangia
of C. nigra mounted on long capillary stipes always droop more or less;
the sporangia of the present species stand rigidly erect. The sporangia
vary in form and in the branching of the columella. In the more globose
phases, the columella almost always shows a peculiar dichotomy near
the apex; in the cylindric types, this peculiar division fails. In fact,
the shape is determined chiefly by the mode of branching of the colu-
mella. Rostafinski's figure, on pi. XIII, does not present the type
usually seen in this country, nor even in Europe if we may judge from
later illustrations. Celakowsky's illustrations (Myx. Bohm. pi. 2,
figs. 7, 8) are better.

The species with us has received various names, but so far as can be
determined, all apply to the same thing, and comparison of specimens
from Mr. Ellis with those from Europe shows the correctness of the
nomenclature here adopted.

The var. rigida Brandza is characterized by scanty, rigid capillitium
and slightly larger spores.

Forms with larger spores have been reported, including a form with
very minute globose sporangia, a scanty capillitium and spores 12-14 /x
in diameter, described by Meylan (Bull. Soc. Vaud. Sc. Nat. 53 : 456,
1920) as var. microcarpa. This may prove to be distinct.

Rare, but widely distributed in North America; also Europe,
Malay Peninsula, Manchuria, Japan.

178 THE MYXOMYCETES

9. Comatricha cornea G. List. &" Cran.

Jour. Bot. 55 : 121. 1917.

Sporangia scattered or solitary, stalked, globose, 0.12-0.32 mm. in
diameter; stalk subulate, straight, slender, 0.17-0.2 mm. high, dark
brown above, brownish yellow below where it expands into a discoid
hypothallus; columella brown, cylindrical, reaching one-third to one-
half the height of the sporangium, with a small collar where it meets
the stalk, dividing above into two or three primary branches of the
capillitium; branches forking repeatedly and ending at the surface in
short, rigid, diverging branchlets; spores gray, minutely warted, the
spore wall thinner on one side, 8.5-9 fx.

Scotland, Germany, Switzerland.

10. Comatricha fimbriata G. List. & Cran.

Jour. Bot. 55 : 122. 1917.

Sporangia scattered, stalked, globose, blackish brown, 0.1-0.35 mm.
in diameter; stalk black, subulate, slender, straight or curved, 0.5-1
mm. high; capillitium arising chiefly from the summit of a short
truncate columella, consisting of a scanty tuft of purplish brown
threads, extremely slender at the base, simple or forking below the
clavate or irregularly expanded tips; spores grayish purple, closely and
minutely spinulose, paler and smoother on one side, 10-12 yu. Plas-
modium colorless.

Collected from several localities in Iowa by Mr. H. C. Gilbert and
the junior author on the bark of trees brought into the laboratory
where it develops after a few days in a moist chamber. The curious
capillitium is like that of no other species. Aside from the Iowa collec-
tions, known only from England and Scotland.

11. Comatricha suksdorfii Ellis & Everh.

Bull. Lab. Nat. Hist. Washburn Coll. 1 : 5. 1884.
PL XII, Figs. 291, 292.

1892. Stemonitis suksdorfii (Ell. & Ev.) Massee, Mon. 76.
1894. Comatricha obtusata Preuss ex List., Mycetozoa 117.
1907. Comatricha nigra (Pers.) Schroet. var. suksdorfii Sturgis, Colo. Coll. Pub.
Sc. Ser. 12 : 33. 1907.

Sporangia scattered in small tufts or gregarious, cylindric or clavate,
obtuse at both ends, black, 2-6 mm. tall, stipitate; stipe jet-black,
shining, even, usually about one-half the total height, sometimes
shorter; hypothallus not continuous, dark brown; columella black,
rather slender, terminating in two or more large branches just below

COMATRICHA 179

the apex; capillitium arising from entire length of columella, exceed-
ingly dense, dark fuscous or black, the flexuous threads anastomosing
in a close network, with abundant free pallid extremities; spores in
mass blue-black, by transmitted light fuscous or dark violaceous
brown, paler on one side, minutely warted, 10-12 jx.

Easily recognizable at sight by its sooty color. Entirely unlike any
of the preceding. The capillitium is similar to that of C. pulchella, but
it is very much more dense and entirely different in color. The sporan-
gia are often widened above and fairly truncate ; the total height up to
6 mm. The peridium is colorless, usually evanescent, but sometimes
long-persistent; when free, white or silvery.

Var. aggregata Meylan has the sporangia confluent, on very short
stipes, and a more lax capillitium. It is connected by intermediate
forms with the typical form, and seems unworthy of recognition.

On coniferous wood, Washington, Oregon, Colorado; Switzerland.

12. Comatricha pacifica Macbride

Amer. Jour. Bot. 19 : 139. 1932.
1922. C. aqualis Peck var. pacifica Macbr., N. A. Slime-Moulds ed. 2. 181.

Sporangia gregarious, erect, deep violaceous, cylindrical or slightly
ovate, 7-8 mm. tall, stipitate; stipe about half the total height, black,
polished, even; hypothallus dark brown, shining, conspicuous, more
or less distinct for each sporangium, often connected in plasmodio-
carpous fashion but not continuous; columella dark, tapering, attaining
almost the summit of the sporangium; capillitium dense, of dark flex-
uose threads, branching repeatedly and forming an intricate network,
the free ends numerous, short, little if any paler than the threads from
which they arise; spores dark violaceous, distinctly warted, 9.5-11 /j..

Resembling C. aqualis, of which it was formerly regarded as a vari-
ety, but larger, darker, more distinctly purple, and with a different
hypothallus and larger spores.

Oregon, M. E. Peck.

13. Comatricha reticulata Gilbert

Amer. Jour. Bot. 19 : 140. 1932.

Sporangia dark lilac-brown, in small loose tufts, erect, on a thin
silvery hypothallus, 1.5-3 mm. tall, short-cylindric and obtuse at
both base and apex; stipe about one-half the height, black, shining;
columella dissipating in the upper one-fourth of the sporangium;
primary branches of the capillitium numerous, often thickened near
the columella, and branching and anastomosing to form an irregular

180 THE MYXOMYCETES

net toward the surface which retains the form of the sporangium after
spore dispersal; free tips outside the net short and abundant; spores
pale lilac-brown, strongly reticulate with meshes of irregular size,
7-9 (j. in diameter.

The network of the capillitium suggests Stemonitis but is decidedly
not on the surface, as is shown by the many free tips outside the net.
The beautifully reticulate spores constitute the most striking charac-
teristic of this species.

Oregon. On rotting coniferous wood.

14. COMATRICHA FRAGILIS Meyldfl

Bull. Soc. Vaud. Sc. Nat. 56 : 70. 1925.

1910. Comatricha laxa Rost. var. microspora Torrend, Bull. Soc. Vaud. Sc.
Nat. 46 : 50. 1910.

Sporangia in groups, sometimes rather large, sooty, 2 mm. tall,
subcylindrical, borne on a stalk equally or almost as long; columella
attaining summit of sporangium; capillitium as in C. nigra but falling
with the spores and leaving the columella naked except at the summit
where it sometimes remains attached longer as in Enerthenema; spores
sooty, 4-6 [x, rarely 5-8 ix.

An authentic collection from Dr. Meylan has spores of nearly
uniform size, averaging 7.5 fx. The sooty sporangia with the capil-
litium persistent only in the upper part are as described.

Jura Mountains, Switzerland.

15. Comatricha ^equalis Peck

Rept. N. Y. State Mus. 31 : 42. 1879.

1892. Stemonitis (zqualis (Pk.) Massee, Mon. 80.

1907. Comatricha nigra (Pers.) Schroet. var. cequalis Pk. ex Sturgis, Colo.
Coll. Pub. Sc. Ser. 12 : 34.

Sporangia gregarious, seldom erect, usually inclined, curved or
nodding, dark brown, becoming violet, cylindric, acuminate-obtuse,
4-6 mm. tall, stipitate; stipe about half the total height, black, pol-
ished, even; hypothallus well developed, brown, continuous; columella
black, tapering gradually, and attaining almost the summit of the
sporangium; capillitium dense, of flexuous tawny threads which, by
repeated branching, form an intricate network, the free extremities
numerous, short and pale; spores dark violaceous, distinctly warted,
7.5-8 ix. Plasmodium milky white.

A very graceful, elegant species, related to C. pulchella, but distinct
by its much greater size and smaller spores. The specimens before us
show the perfection of beauty in this genus; the polished stipe, the

COMATRICHA 181

symmetrical capillitium, the soft purple-brown tints are remarkable,
and enable one to recognize the form at sight.
New York, Pennsylvania, Ohio, Illinois; Rumania.

16. COMATRICHA SUBCCESPITOSA Peck

Rept. N. Y. State Mus. 43 : 25. 1890.
PI. XII, Figs. 295, 296.

1892. Stemonitis subccespitosa (Pk.) Massee, Mon. 80.

1894. Comatricha obtusata Preuss ex Lister, Mycetozoa 118, in part.

1909. Comatricha persoonii Rost. var. subccespitosa Peck, ex Torrend, Fl. Myx.

137.
1922. Comatricha nigra Schroet. var. subccespitosa Lister, Mycetozoa ed. 3. 142.

Sporangia scattered or sometimes in loose clusters, cylindric, obtuse,
1.5-2 mm. tall, dark brown, stipitate; stipe short, one-fifth total
height; hypothallus minute; capillitium regular, the branching quite
uniformly parallel, flexuous, brown with a tinge of violet, not dense;
columella well defined, almost percurrent; spores brown in mass, under
lens dusky, nearly smooth, 8-10 fx.

The larger spores, regular, erect form, and clustered habit separate
this form from others with which it will be naturally associated.

Nova Scotia, New York, California?; Europe?.

17. Comatricha nigra (Pers.) Schroet.

in Cohn, Krypt. Fl. Schles. 3 (1) : 118. 1885.
PI. XII, Figs. 297, 298.

1791. Stemonitis nigra Pers., in Gmel., Syst. Nat. 2 : 1467.

1794. Stemonitis atrofusca Pers., Roemer N. Mag. Bot. 1 : 91.

1801. Stemonitis ovata Pers., Syn. Meth. Fung. 189.

1803. Trichia mucoriformis Schum., Enum. PI. Saell. 2 : 211.

1829. Stemonitis oblonga Fr., Syst. Myc. 3 : 159.

1875. Comatricha friesiana Rost., Mon.199.

1893. Comatricha persoonii var. gracilis Cel. fil., Myx. Bohm. 50, pi. 2, figs. 4, 5.

Sporangia scattered, ferruginous or dark brown, globose or ovoid,
stipitate, mostly 2-4 mm. tall; stipe long, hair-like, tapering upward,
black; hypothallus none; columella rapidly diminished toward the
top, at length dissipated; capillitium of slender flexuous threads
radiating horizontally, repeatedly branching and anastomosing to
form an intricate dense network, from the surface of which project a few
short hook-like peridial processes; spore-mass black; spores by trans-
mitted light dark violaceous, smooth or nearly so, 7-10 /a. Plasmodium
colorless, then white.

This species, when typical, is easily recognized by its almost globose
sporangia mounted on long slender stalks. These are 2 or 3 mm. high

182 THE MYXOMYCETES

and generally persist, as Persoon noticed, a long time after the spo-
rangium has fallen. The sporangia are at first black; after spore dis-
persal pale ferruginous. In shape they vary from ovate to spherical.
Sometimes they are umbilicate below, so that a vertical section would
be obcordate. Care must be taken to distinguish the present species
from blown-out forms of Lamproderma.

This most common species seems to be also the center of wid-
est differentiation. In a valuable paper on the Myxomycetes of
Dr. C. H. Peck's herbarium, Dr. Sturgis (1900) points out the vary-
ing relationships of a group of surrounding forms. According to his
account C. nigra approaches C. laxa at one extreme, C. cequalis, which
the Listers enter as varietal here, at the other. However, in the
former the more rigid, direct and simple branching from the columella
is usually determinative; in the latter the color, form and generally
more delicate structure, and a tendency to grow in tufts will serve to
distinguish it.

In this discussion we have assumed as typical the globose sporan-
gium, with the variations in the direction of ovate, obovate, ellipsoidal,
etc., the capillitium flexuous and more richly anastomosing near the
columella. On the drier slopes in the mountains of Colorado specimens
are especially abundant, in proper season covering apparently the
lower surface of every barkless twig or fallen stem or even entire trees.
In such a field one might imagine every possible variation open to
observation. Probably such is the case; but as a matter of fact a single
small Plasmodium at lower levels will sometimes show greater range
of variation than was noted on the mountain side. The cylindric
forms were for some reason few, and when noted were short, though
often surmounting stems of double the usual length.

Rostafinski calls this C. friesiana, using the specific name suggested
by de Bary. By this name the species was commonly known for many
years. It was previously distributed by Rabenhorst as Stemonitis
friesiana de Bary, but this name seems not to have been validly pub-
lished. More recently some writers prefer C. obtusata Preuss; but
C. obtusata Preuss, as figured by that author (Sturm's Deutsch. Fl.,
pi. 70), is surely more likely Enerthenema papillatum, and the author
says in his description "capillitio vertice soli innato." Persoon cer-
tainly recognized the species, and his description, though brief, is yet
applicable to no other European species. There seems no reason why
the name he gave should not be permanently adopted. Rostafinski's
figure, pi. XIII, shows an ellipsoidal sporangium, not cylindric.

A form with very short stipe and large spores, 10-11 fx, was described
by Meylan as the var. brachypus. Later, finding the characters con-

COMATRICHA 183

stant, he proposed it as a distinct species, C. brachypus (Bull. Soc.
Vaud. Sc. Nat. 57 :41, 1929).

C. nigra is widely distributed and not uncommon, but often over-
looked. Eastern United States to Colorado and on the Pacific coast,
Bolivia, Brazil, Argentina; widely distributed in the old world.

18. COMATRICHA ELLISII Morg.

Jour. Cin. Soc. Nat. Hist. 16 : 133. 1894.

1899. Comatricha laxa Rost. ex Macbr., N. A. Slime-Moulds 127, non Rost.
1911. Comatricha nigra (Pers.) Schroet., ex Lister, Mycetozoa ed. 2. 152, in

part.
1922. Comatricha laxa Rost. ex Lister, Mycetozoa ed. 3. 143, in part.

Sporangia short, erect, oval or ovoid to oblong, total height 0.6-
1.5 mm.; stipe and columella erect, brown and smooth, rising from a
thin pallid hypothallus, tapering upward and vanishing into the
capillitium toward the apex of the sporangium, the stipe usually
longer than the columella; capillitium of slender pale brown threads
which branch several times with lateral anastomosing branchlets,
forming a rather open network of small meshes, ending with very short
free extremities; spores globose, even, pale ochraceous, 6-7 ju.

Growing on old pine wood, the sporangium 0.3-0.6 mm. in height
by 0.3-0.5 mm. in width, the stipe usually a little longer than the
sporangium.

v On the strength of the clear descriptions and beautiful drawings of
Celakowsky, Myxomyceten Bohmens, p. 52, pi. 2, figs. 7 and 8, this
elegant little species was formerly referred to C. laxa Rost. It was
then reported from New Jersey only. Since then we have specimens
from southern Missouri, all true to form, almost identical. It seems
wise accordingly, while recognizing the relationship of the form both
to C. laxa, and to C. nigra, to give it here an individual place again.
It is very small; but once studied may thereafter be easily recognized
by a hand lens. The form is definite, clean cut, and the spores are
distinctly smaller than in either of the two related species.

Rare. New Jersey, Missouri.

19. Comatricha lurtda Lister

Mycetozoa 119. 1894.

Total height 1.25 mm.; sporangia scattered, globose or shortly
ovoid, erect, 0.5 mm. in diameter, stalked, purplish brown; sporangium
wall evanescent; stalk setaceous, black, shining, 0.75 mm. long, rising
from a circular brown hypothallus; columella cylindrical, reaching to

184 THE MYXOMYCETES

half the height of the sporangium, dividing into stout branches at the
apex and continued into the capillitium; latter dark purplish brown
throughout, spreading from the upper part of the columella in flexu-
ous anastomosing threads, with slender brown free ends; spores
spherical or subovoid, purplish gray, coarsely warted, 6-10 fx.

The range of spore-size, as given by Lister, is rather wide. The
species is said to resemble Lamproderma scintillans.

Europe, Japan.

20. Comatricha elegans (Racib.) List.

Guide Brit. Mycetozoa ed. 3. 31. 1909.
PI. XII, Figs. 299, 300.

1884. Rostqfinskia elegans Racib., Rozpr. Akad. Krak. 12 : 77.
1888. Raciborskia elegans Berl., Sacc. Syll. Fung. 7 : 401.

Sporangia loosely gregarious, globose, stipitate, purplish brown,
0.3-0.5 mm. in diameter, 1-2 mm. in total height; stipe black, su-
bulate, to 1.6 mm. ; columella at first divided into a few main branches,
from which by repeated subdivision the delicate, anastomosing, flex-
uose capillitial threads take origin; spores pale brownish violaceous,
spinulescent, 8-10 fx.

In a collection from Virginia, the silvery peridium tends to persist,
as in a lamproderma.

New Jersey, Virginia, South Carolina, Colorado, Washington;
Europe, southern Asia, Japan.

21. Comatricha typhoides (Bull.) Rost.

Vers. 7. 1873.
PI. XII, Figs. 293, 294.

1791. Trichia typhoides Bull., Champ. 119. pi. 477, fig. 2.

1805. Stemonitis typhoides (Bull.) DC, Fl. Fr. 2 : 257.

1842. Stemonitis pumila Corda, Icones 5 : 59.

1875. Comatricha typhina Rost., Mon. 197.

1875. Comatricha affinis Rost., Mon. 202.

1885. Comatricha stemonitis (Scop.) Wettst., Verh. Zool.-Bot. Ges. Wien
35 : 534.

1892. Stemonitis affinis Massee, Mon. 76.

1892. Stemonitis atra Massee, Mon. 78.

1892. Stemonitis carlylei Massee, Mon. 84.

1899. Stemonitis platensis Speg., Anal. Mus. Nac. Buenos Aires 6 : 202.

Sporangia gregarious or scattered, stipitate, cylindrical or some-
times narrowly ovate, erect or sometimes arcuate, obtuse, 2-3 mm.
high, at first silvery, then brown as the peridium vanishes; stipe black,
about one-half the total height or less; hypothallus distinct, more or

COMATRICHA 185

less continuous, reddish brown; columella tapering upward, black,
attaining more or less completely the apex of the sporangium; capil-
litium arising as rather stout branches of the columella, soon taking
the form of slender, nexuous, brownish threads, which by repeated
anastomosing form at length a close network, almost as in Stemonitis,
the free, ultimate branches very delicate and short; spore-mass dark
brown; spores by transmitted light pale, almost smooth, except for
the presence of a few scattered but prominent clusters of warts, of
which four or five may be seen at one time, 5-7.5 /jl.

This is our most common North American species. It occurs every-
where on decaying wood, sometimes in remarkable quantity, thou-
sands of sporangia at a time; sometimes on leaves. The plasmodium,
watery white in color, infests preferably very rotten logs of Quercus,
on which in June the sporangia rise as white or pallid columns. The
peridium is usually exceedingly delicate, less seldom seen here than
in some other species, it is true, but easily overlooked; occasion-
ally it tends to persist. The spores when fresh have a distinct violet
or bluish tinge; in old specimens they are almost colorless. In any
case they are well marked by the clustered warts.

This is probably Mucor stemonitis Scopoli (1772), although the
description is scarcely diagnostic. But Scopoli, by citing Hall, Gleditsch
and Micheli, so defines the form as to leave small doubt that he had
before him our common species. Schaeffer's figures also come to the
rescue, which, though by no means satisfactory, yet can probably refer
to no other species. Stemonitis typhina Wiggers (1780) also seems to
be this species and this specific name is adopted by Persoon and
Rostafinski. However, Bulliard gives the first good account and figure,
and in accordance with the decision of our English colleagues, the name
used in the famous Champignons is here retained.

Widely distributed. Nova Scotia to Washington, south to Nicaragua,
British Guiana, Brazil and Argentina; common in the old world.

22. Comatricha rubens Lister

Mycetozoa 123. 1894.

Sporangia gregarious, globoid or ellipsoidal, 1-1.5 mm., pink-brown,
stipitate; peridium persistent below; stipe 0.5-1 mm., black, shining;
columella more than half the sporangium in height, giving off on all
sides the brownish violaceous, flexuose threads of the capillitium,
somewhat thickened and broadly attached to the persisting peridial
cup; spores lilac-brown, spinulescent, 7-8 m-

Somewhat resembling a lamproderma, but the capillitium arising

186 THE MYXOMYCETES

from all parts of the columella. Close to C. pulchella, but distinguished
by the elliptical or globose peridium and its persistent base.
Pennsylvania, Colorado; Great Britain, Switzerland.

23. COMATRICHA TENERRIMA (Curt.) G. List.

Guide Brit. Mycetozoa ed. 4. 39. 1919.

1848. Stemonitis tenerrima Curt., Am. Jour. Sc. II. 6 : 352.

1911. Comatricha pulchella (Bab.) Rost. var. tenerrima List., Mycetozoa ed. 2.
156.

Sporangia scattered, stalked, ovoid or cylindrical, pale red, brown-
ish pink or lilaceous, equalling or shorter than the slender black stalks;
total height 1.5-2 mm.; columella slender, often reaching the summit
of the sporangium; capillitium a network of slender, flexuose, pale
red threads; spores pale flesh colored, minutely warted, 7-8 ix.

On dead herbaceous stalks and dead wood. Pennsylvania, South
Carolina, Antigua, Brazil; Europe, Japan.

24. Comatricha pulchella (Bab.) Rost.

Mon. App. 27. 1876.
PI. XIII, Figs. 301, 302.

1837. Stemonitis pulchella Bab., Trans. Linn. Soc. 1 : 32.
1875. Comatricha persoonii Rost., Mon. 201.

Sporangia very minute, 1-1.5 mm. high, scattered, ovate to short-
cylindric, acuminate, pale brown or ferruginous, stipitate; stipe short,
black, nearly even; hypothallus none, or merely a circular base to the
tiny stem; columella straight, gradually tapering, reaching almost if
not quite the apex of the sporangium; capillitium dense, a network of
flexuous brown threads, rather broad within, ending in slender tips
without; spore-mass brown; spores by transmitted light pale "lilac-
brown," or pale ferruginous, minutely but uniformly warted, 6-8 fx.
Plasmodium colorless.

The var. fusca Lister is said to have a darker and more rigid cap-
illitium. Var. gracilis Lister is narrowly cylindrical, with partially
formed surface net and smaller spores.

Probably widely distributed but rarely collected. New Jersey,
Pennsylvania, Ontario, Ohio, Iowa, Missouri, Colorado, Bolivia;
Europe, Nigeria, southern Asia, Japan.

Family LAMPRODERMACE^E
Sporangia distinct, usually gregarious, more or less spherical,
usually stalked; columella typically present, rarely absent; capillitium
composed of slender, more or less branching threads, arising chiefly

DIACHEOPSIS 187

or solely from the summit of the columella, when latter is present,
otherwise from the base of the sporangium.

The typical members of this family are very close to the Stemoni-
tacea?. Certain species of Lamproderma and of Comatricha approach
the other genus rather closely. In general, however, the lamproder-
mas have the capillitial branches concentrated at or near the tip and
possess a more persistent and usually iridescent membrane.

The genus Diacheopsis, judging from the description, is a sessile
or nearly sessile lamproderma without columella. Echinostelium
may or may not belong in this family, but may at least be tempo-
rarily accommodated.

KEY TO THE GENERA OF THE LAMPRODERMACE^E

a. Sessile on a broad base or short-stalked; columella lacking. . 1. Diacheopsis
a. Stipitate, or rarely sessile on a narrowed base; columella

present "

b. Columella percurrent; capillitium arising from a disk at

its apex 2. Enerthenema

b. Columella rarely exceeding the center of the sporangium c

c. Columella very short; capillitium forking but not forming a

net d

c. Columella \i to Y 2 the height of the sporangium «

d. Minute, 100 n or less in height; capillitium rudimentary. . 3. Echinostelium
d. Larger; capillitium brush-like, rigid, the threads bearing
circular disks at their tips derived from the sporangium
wa ll 4. Clastoderma

e. Peridium dark, dehiscing in persistent lobes; capillitium dark,

scanty, simple 5. Barbeyella

e. Peridium iridescent, fragile; capillitium dense, often branch-
ing and anastomosing freely 6. Lamproderma

1. Diacheopsis Meylan
Bull. Soc. Vaud. Sc. Nat. 57 : 149. 1930.

Sporangia globose, sessile or stalked; peridium membranous, per-
sistent, shining with metallic luster; columella lacking; capillitium of
branching and anastomosing threads as in Lamproderma, but these
arising from the base of the sporangium; spores dark.

Except for the absence of a columella the genus appears to be very
close to Lamproderma.

A single species: —

Diacheopsis metallica Meylan

Bull. Soc. Vaud. Sc. Nat. 57 : 149. 1930.
Sporangia clustered, subglobose, sessile, broader than high, 1-2 mm.
in diameter, dark blue, with metallic green, pale blue, purple or gold

188 THE MYXOMYCETES

reflections; peridium membranous, transparent, free from the capil-
litium as in Lamproderma; columella completely lacking; capil-
litium arising from the base of the sporangium, the filaments almost
colorless, anastomosing, especially toward their outer ends, and fre-
quently with triangular enlargements at the junctions; spore-mass
bluish black; spores blackish purple, covered with cylindrical papil-
lae 1 jii in length, 12-14 /jl in diameter.
Swiss Alps.

2. Enerthenema Bowman

Trans. Linn. Soc. 16 : 152. 1828.

Sporangia stipitate, the stipe extended as a columella, which en-
tirely tranverses the sporangium and forms at the apex an expanded
disk; from this depends the capillitium.

KEY TO THE SPECKS OF ENERTHENEMA

a. Color fuscous to violaceous or ferruginous; spores mi-
nutely warted, not clustered I.E. papillatum

a. Color black; spores rough b

b. Spores not clustered, dark, coarsely verrucose 2. E. melanospermum

b. Spores clustered; exposed area long-spinescent 3. E. berkeleyanum

1. Enerthenema papillatum (Pers.) Rost.

Mon. App. 28. 1876.

(as £. papillata)

PI. XIII, Figs. 305, 306.

1801. Stemonitis papillata Pers., Syn. Meth. Fung. 188.

1828. Enerthenema elegans Bowman, Trans. Linn. Soc. 16 : 152.

1888. AncyropJwrus crassipes Raunk., Bot. Tidsskr. 17 : 93.

Sporangia fuscous, becoming more or less ferruginous when blown,
globose, stipitate, 0.5-0.7 mm. in diameter, 1-1.5 mm. tall, tipped
with the small, shining cupulate or rarely papillate apex of the col-
umella; stipe black, opaque, attenuate above, about equal to the
peridium; the basal portion of the sporangium wall often remaining
as a ring around the stem after dehiscence; columella slender, cylin-
drical, unbranched, expanding at the apex into a disk from which the
capillitial threads arise; these long, slender, sparingly branched, more
or less nexuose, dark with free tips ; spores olivaceous fuscous, minutely
warted, 10-12 fi.

The papilla referred to in descriptions, and from which the name is
derived, seems to be nothing more than the disk-like top of the cap-

ENERTHENEMA 189

illitium, from which the sporangial mass has slipped, leaving it pro-
truding slightly.

Meylan has described a variety carneogriseum (Bull. Soc. Vaud.
51: 268, 1917) as differing from the typical form by its rose-gray or
violet sporangia. We have collections that approach that condition,
but they merge into the typical condition.

Not common but widely distributed. From Pennsylvania and
South Carolina to Iowa, Colorado and Washington, Chile; through-
out the north temperate zone.

2. Enerthenema melanospermtjm Macbride & Martin

Jour. Wash. Acad. Sc. 22 : 91. 1932.
PL XIII, Figs. 307, 308.

Sporangia intense black, gregarious in small clusters of three to a
dozen, these in larger aggregations, globose or oval, stalked, 0.8 to
1 mm. in diameter, total height 2 mm. or more; stipe black, shin-
ing, rather stout, attentuated upward and continued as a slender,
unbranched columella capped with a very large, shining, infundibuli-
form terminal disk, up to 0.5 mm. in diameter; capillitium dense,
black, rather freely branched, arising from terminal disk and with
ends free; spores free, dark olivaceous, coarsely warted, 12-14 /x.

Obviously close to E. papillatum but clearly distinct by reason of
its large size, the intense and permanent black color, the very large
apical disk, and the large, dark, very rough spores.

Oregon, Washington.

3. Enerthenema berkeleyanum Rost.

Mon. App. 29. 1876.
(as E. berkeleyana)

1913. Enerthenema syncarpon Sturgis, Colo. Coll. Pub. Sc. Ser. 12 : 448.
1925. Enerthenema papillatum Rost. var. syncarpon List., Mycetozoa ed. 3. 150.

Sporangia jet-black, gregarious or scattered, globose, stalked,
rather small, diameter 0.4-0.7 mm., height 0.8-1 mm.; stipe black,
extending into columella which is tipped by a small shining disk from
which the black, coarse, rough, sparsely branched, flexuose capilli-
tium descends; spores in clusters of 4-12, very spiny on exposed sur-
faces, nearly smooth elsewhere, becoming globose when separated
and then 11-13 ju in diameter.

Distinct from E. papillatum in color, and capillitial and spore char-
acters.

Rare: South Carolina, Colorado, also two collections from Long

190 THE MYXOMYCETES

Island reported by Mr. Hagelstein, in both cases on lumber from
other localities, one of these being Nova Scotia.

3. Echinostelium de Bary
in Rost., Versuch 7 : 1873.

Sporangia distinct, globose, minute, the structure limited to a few
imperfect rib-like, loosely joined branches developed from the short
columella or stem-top, sustaining the spores.

A single species: —

Echinostelium minutum de Bary

in Rost., Mon. 215. 1875.
PI. XXI, Figs. 552, 553.

Sporangia distinct, scattered, globose, very minute, 40-50 fx, stipi-
tate; stipe hair-like, subulate, granular but hyaline; columella minute
or none; capillitium consisting of a few arcuate spinose threads, loosely
united, supporting the uncovered spores; spores globose, pinkish or
colorless, smooth, 7-8 jjl.

Originally discovered by de Bary in Germany, it has since been re-
ported from several localities in Great Britain, Austria and Rumania.
In North America it has been collected from five widely scattered
localities, once by Professor Thaxter on a laboratory culture from
Maine, again by Mr. Bilgram in Philadelphia and a number of times
by the junior author and by Mr. H. C. Gilbert on bark and wood from
Vermont, West Virginia and Iowa. Apparently common and wide-
spread, but because of its extreme minuteness rarely reported.

4. Clastoderma Blytt
Bot. Zeitung 38 : 343. 1880.
Sporangium globose, distinct, stipitate; columella short or obsolete;
capillitium of few sparsely branched threads, which bear at their tops
the persistent fragments of the peridium, but are not otherwise united.
Distinguished from Lamproderma by the peculiar manner in which
the peridium is ruptured, and by the simplicity of the scanty capilli-
tium. So far there appears to be but a single species.

Clastoderma debaryanum Blytt

Bot. Zeitung 38 : 343. 1880.
PI. XXI, Fig. 554.

1886. Orthotricha microcephala Wing., Jour. Myc. 2 : 125.

Sporangia scattered or gregarious, very minute, 0.1 to 0.2 mm. in
diameter; peridium fugacious, except for the minute circular or po-

BARBEYELLA 191

lygonal patches that adhere to the capillitial branchlets, and the slight
annulus at the base of the columella; stipe long, unequal, dark below,
above paler; columella almost none, giving rise to the comparatively
few slender threads which by their repeated forking make up the
capillitium; spores globose, even, violaceous, 8-9 /x.

Reported in the United States so far from Maine, New York, Penn-
sylvania, Ohio, Illinois, Iowa, Chile; Europe, Asia, Australasia. Mr.
Hagelstein reports it as abundant on Long Island.

The sporangia are very small, but beautiful, delicate little struc-
tures, found mainly on bark in this country; in Norway it seems to
have been seen first on a dead polyporus. Its minuteness doubtless
causes it to be generally overlooked.

The var. imperatoria Emoto (Bot. Mag. 43 : 172, 1929) is somewhat
more robust, with spores 10 ix in diameter, and with strongly netted
plates.

5. Barbeyella Meylan
Bull. Soc. Bot. Geneve 2 ser. 6 : 89. 1914.

Sporangia subglobose, stalked, the walls dehiscing into somewhat
persistent lobes; capillitium consisting of a few simple dark threads
radiating from the summit of the columella.

Barbeyella minutissima Meylan

Bull. Soc. Bot. Geneve 2 ser. 6 : 89. 1914.
PI. XVI, Figs. 395, 396.

Sporangia scattered, stalked, subglobose, 0.15 to 0.2 mm. in di-
ameter; sporangium wall membranous, dark purplish brown, dehisc-
ing by breaking up into a few irregular lobes and plates; stalk black,
subulate, solid above, tubular and enclosing refuse matter below,
0.2 to 0.6 mm. tall; columella black, about half the height of the spo-
rangium, cylindrical or thickened at the summit; capillitium of 7 to 10
dark, simple or rarely forked threads radiating from the top of the
columella and adhering by their tips to the sporangium wall; spores
pale purplish gray covered with rather sparse, dark, coarse warts,
7-9 (x, sometimes nearly smooth.

Our specimens, received through the courtesy of M. Meylan, have
rough spores uniformly 8.5 to 9.2 /x in diameter. The details of the
dehiscence are described by Jarocki (1931).

Known only from the Jura Mountains of Switzerland, from Poland,
in the latter country occurring both in the Carpathians and in the
lowlands, and from Japan.

192 THE MYXOMYCETES

6. Lamproderma Rost.

Versuch 7. 1873.
Sporangia stipitate, rarely sessile, globose or ellipsoid ; columella
cylindric or sometimes clavate, scarcely attaining half the height of
the peridium; peridium shining with metallic tints, deciduous, except
where, at the base of the columella, it forms a ring around the stipe;
capillitium rising in tufts or by simple branches mainly from the tip
of the columella, the threads regularly forked, generally united into

a net.

The lamprodermas are distinguished from the comatrichas, to which
they are most nearly allied, by the arrangement of the capillitium,
its development largely from the apex of the columella, the continua-
tion of the stipe within the peridium. In other words, the peridium
leaves the stipe some distance below the point where the lowest capil-
litial branches take origin. In mature specimens the peridium has
often entirely disappeared, its only trace a more or less distinct collar
around the stipe marking the beginning of the columella. Neverthe-
less the peridium is far more persistent than in any comatricha, and
shows in yet greater brilliancy the wondrous metallic tints and iri-
descence of Comatricha and Diachea. Older authors, so far as can be
seen, distributed the species between Physarum and Stemonitis.

Meylan, who has devoted much attention to the genus and has
described a number of new species, is of the opinion that many of
the older names have been used to designate what are in reality ag-
gregates of several species which must eventually be recognized. The
difficulties in the way of deciding which are constant characters and
which are variations induced by changes in the environment are so
great, however, that it seems wise to be conservative in recognizing
newly proposed forms. Meylan 's species are therefore mentioned in
connection with the forms within which they would seem to be included
according to older usage.

KEY TO THE SPECIES OF LAMPRODERMA

a. Spores reticulated or marked with raised bands or lines of

warts "

a. Spores warted, spinulose or nearly smooth • • • d

b. Reticulation complete, regular 1. L. cribrarioides

b. Reticulation incomplete or replaced by lines c

c. Peridium thin, membranous, dark gray; spores covered

with warted vesicles, the warts in lines or circles 2. L. cristatum

c. Peridium somewhat thicker, fragile, dull; spores incom-
pletely reticulate with lines of warts 3. L. atrosporum

d. Spores coarsely echinulate, 14-20 n e

d. Spores finely warted or echinulate, usually under 15 /z i

LAMPRODERMA 193

e. Stalked; peridium iridescent; spores 15-20 /z 4. L. echinulatum

e. Usually sessile /

/. Iridescent; columella lacking; spores 18-19 n 5. L. insessum

/. Dull; columella well developed; spores 14-16 /x 6. L. echinosporum

g. Peridium netted, silvery blue over black 7. L. gulielmce

g. Peridium not netted h

h. Stipe scarcely exceeding height of sporangium, some-
times very short or lacking i

h. Stipe as a rule greatly exceeding height of sporangium,

sometimes short j

i. Sessile; sporangia ovate, taller than wide; capillitium

dense, dark 8. L. carestice

i. Peridium thin, iridescent; capillitium delicate, pale;

spores pallid, 8-11 n 9. L. violaceum

i. Peridium firmer, blue or bronze; capillitium coarse, ap-
pearing hoary; spores dark, mostly 10-15 n 10. L. sauteri

j. Columella divided at tip into several primary branches

of the dense capillitium 11. L. arcyrionema

j. Columella undivided ; capillitium not dense, the numer-
ous branches arising directly k

k. Stipe slender, smooth, thread-like; sporangia very small 12. L. scintillans
k. Stipe thick, rough, stuffed; larger /

/. Columella swollen, obtuse; capillitium simple, rigid. . . 13. L. physaroides

I. Columella slender, tapering; capillitium branching

freely 14. L. columbinum

1. Lamproderma cribrarioides (Fr.) R. E. Fries

Svensk. Bot. Tidssk. 4 : 259. 1910.
PI. XIII, Figs. 309, 310.

1829. Stemonitis cribrarioides Fr., Syst. Myc. 3 : 163.

1888. Lamproderma lycopodii Raunk., Bot. Tidsskr. 17 : 90.

Sporangia scattered or clustered, globose, 0.8-1 mm. in diameter,
sessile or occasionally with very short stalks, rarely plasmodiocar-
pous, purple-brown, iridescent; sporangium wall membranous, color-
less above, purplish brown below; stalk, when present, black, often
flattened or membranous, 0.1 to 0.6 mm. high; columella cylindrical,
penetrating the sporangium to half or two-thirds of its height, absent
in the plasmodiocarpous form; capillitium a network of pale purplish
brown flexuose threads which are stouter below, slender and colorless
at the tips; spores dark purplish brown, 11-16 n in diameter, regularly
reticulated with narrow raised bands that form a net with from 8 to 24
meshes to the hemisphere and that show as a border 0.5 to 1.5 /x wide.

The dark, reticulate spores are characteristic. Miss Lister says they
are from 11 to 18 ju in diameter, a very wide range; Raunkiaer says
12-18 ix, Meylan 11-14/j. In material collected by Seaver and Shope
in Colorado, the sporangia are rather densely clustered and the spores

194 THE MYXOMYCETES

are very uniformly 14-16 /x. In a collection from Rumania they are
even more uniform in size, almost all falling between 14.4 and 15.2 ix.
Colorado; Europe. Mainly Alpine.

2. Lamproderma cristatum Meylan

Bull. Soc. Vaud. Sc. Nat. 53 : 457. 1921.
PI. XIII, Fig. 311.

Sporangia spherical, sessile or with a very short stalk, 1-1.5 mm. in
diameter; peridium thin, membranous, dark gray, early disappearing;
capillitium rather pale, gray or purplish; spores globose, dark purplish,
the surface covered with vesicular, warted crests, appearing more or
less reticulate under the lower powers of the microscope, 12-15 lx.

The spores are unlike those of any other slime mold. Those of our
material, sent by M. Meylan, have the crests smaller and more
densely aggregated than suggested by his illustration or that of
Miss Lister, pi. 216, h, and measuring 14-15 lx.

Switzerland.

3. Lamproderma atrosporum Meylan

Bull. Soc. Vaud. Sc. Nat. 46 : 51. 1910.
PL XIII, Figs. 312, 313.

Sporangia sessile or stalked, globose or oval, 1-1.3 mm. in diameter;
stalks, when present, not exceeding height of sporangia; peridium
fragile, not membranous, fugacious, breaking up into small fragments
some of which adhere to the capillitium, rarely membranous and per-
sistent at base, very dark with silvery sheen; capillitium black or
very dark brown, showing no trace of violet; columella slender, ex-
ceeding the middle; spores dark, strongly warted, the warts arranged
in reticulate lines over a portion of the surface of most of the spores,
11-15 Li. Plasmodium black.

There is wide variation in the spore markings, ranging from a nearly
complete reticulation to a mere trace.

G. Lister and Howard (Jour. Bot. 57 : 25, 27, 1919) describe from
England the varieties debile and anglicum, paler in color.

Oregon; Switzerland, England.

4. Lamproderma echintjlatum {Berk) Rost.

Mon. App. 25. 1876.

1860. Stenionitis echinulata Berk., in Hooker, Fl. Tasm. 2 : 268.
1892. Lamproderma listeri Massee, Mon. 97.

Sporangia loosely clustered, globose, stalked, 0.5-1 mm. in diameter,
2-4 mm. tall, shining, with steel-blue or green reflections; wall mem-

LAMPRODERMA 195

branous, persistent; stalk subulate or cylindrical, black, rising from a
well-developed hypothallus; columella cylindrical, obtuse, about half
the height of the sporangium; capillitium ranging from black to color-
less, arising chiefly from the upper part of the columella; threads
stout, sparingly forked, colorless and slender at the tips; spores dark,
strongly echinulate, 15-20 /x.

Reported from Europe and Australasia.

5. Lamproderma insessum G. List.

Trans. Brit. Myc. Soc. 4 : 41. 1912.

Sporangia sessile, clustered, iridescent purple, subglobose or form-
ing short plasmodiocarps, 0.8 mm. in diameter; wall membranous,
pale purple; columella lacking; capillitium a scanty, loose network of
broad purplish threads, often expanded at the angles and marked
with a few bead-like thickenings; spores dark brownish purple, closely
spinulose, 18-19 ju.

Meylan has found in Switzerland a similar form, but with smaller
spores, which he thinks is an abnormal development of L. columbinum.
Otherwise known only from a single collection. If verified, L. insessum
might well be transferred to Diacheopsis.

Scotland.

6. Lamproderma echinosporum Meylan

Bull. Soc. Vaud. Sc. Nat. 55 : 241. 1924.

Sporangia globose or ovoid, attaining 1 mm. in diameter, sessile or
rarely stalked, dark grayish brown, dull; peridium persistent, mem-
branous, somewhat furrowed; columella reaching half to three-quarters
the height of the sporangium; capillitium dark violaceous brown;
spores purple-black, covered with pointed or obtuse spines 1 /z long,
14-16 /j, in diameter.

The large, dark, spiny spores suggest those of L. echinulatum, from
which the present species is separated by its dull colors and sessile
habit. Meylan regards it as nearly related to L. atrosporum, from
which it differs in its brown persistent peridium, the suggestion of
violet in the capillitium, and its larger, strongly spiny, but not
reticulate spores.

Switzerland.

7. Lamproderma gulielm^e Meylan

Bull. Soc. Vaud. Sc. Nat. 52 : 449. 1919.
PI. XIII, Figs. 314, 315.

Sporangia stipitate, spherical, 0.5 mm. in diameter or less, silvery
blue with black depressed spots; stalk slender, subulate, black, 1-

196 THE MYXOMYCETES

1.2 mm. in length; columella reaching half way to the summit and
giving rise to the pallid or hyaline, branching columella; spores dark
purple, strongly spinulose, 12-15 /x.

A very distinct species, the sporangia when full of spores marked
by a network of silvery blue over black. The nearly transparent wall
often remains in large part after spore discharge. We have seen no
American examples.

Rare: Colorado, ace. to Lister; Europe.

8. Lamproderma carestice (Ces. & de Not.) Meylan

Bull. Soc. Vaud. Sc. Nat. 57 : 368. 1932.
PI. XIII, Figs. 316, 317.

1879. Stemonitis carestice Ces. & de Not., Erb. Crit. Ital. No. 888.
1894. Lamproderma violaceum Rost. var. carestice List., Mycetozoa 130.
1917. Lamproderma sauteri Rost. var. carestice Meylan, Bull. Soc. Vaud. Sc.
Nat. 51 : 264.

Sporangia sessile, ovate, smaller above, 13^-2 times as tall as broad,
violet-blue with shining metallic tints above; columella cylindrical,
about half the height of the sporangium; capillitium dense, dark;
spores papillate, 11-14 /x.

Distinguished from L. sauteri by the elongated, sessile sporangia, the
dense dark capillitium and the paler spores which average somewhat
smaller.

Europe.

9. Lamproderma violaceum (Fr.) Rost.

Vers. 7. 1873.
PL XIII, Figs. 318, 319.

1829. Stemonitis violacea Fr., Syst. Myc. 3 : 162, non Roth 1788, nee Schum.

1803.
1882. Lamproderma nigrescens Sacc, Michelia 2 : 262, non Rost.
1892. Lamproderma saccardianum Massee, Mon. 101.
1892. Tilmadoche berkeleyi Massee, Mon. 332.

Sporangia closely gregarious or scattered, depressed-globose, more
or less umbilicate below, metallic blue or purple, sessile or short-
stipitate, 0.3-1 mm. in diameter; stipe usually rather stout, dark
brown or black, even; hypothallus, when the sporangia are crowded,
a thin, continuous, purplish membrane, when the sporangia are scat-
tered, discoidal; columella cylindric or tapering slightly upward, the
apex obtuse, black, attaining the center of the sporangium; capil-
litium lax and flaccid, made up of flexuous threads branching and
anastomosing to form a network, open in the interior, more dense

LAMPRODERMA 197

without, the threads at first pale brown as they leave the columella,
becoming paler outward to the colorless tips; spores minutely warted,
violaceous gray, 8-11 /x.

This is our most common species; found on decaying sticks and
logs late in the fall. Its pale capillitium will usually distinguish it,
especially where the sporangia are empty; then the pallid free extrem-
ities of the capillitial branches give to the little spheres under the lens
a white or hoary appearance not seen in any other species.

The Plasmodium is at first almost transparent, then amber-tinted,
sending up tiny semi-transparent spheres on shining brownish stalks.
As the changes approach maturity, the sporangia become jet-black,
and only at last when the spores are ready for dispersal does the
peridium assume its rich metallic purple tints. Colonies a meter in
length, two or three decimeters in width, are sometimes seen!

Lamproderma arcyrioides (Somm.) Rost., based on Stemonitis arcy-
rioides Somm. (1827), is said to be this species on the basis of a re-
examination of Sommerfelt's type material. Fries and Rostafinski
regarded them as distinct. The name used here has been generally
accepted, and is for the present retained, as suggested in the English
monograph.

Common in the northern hemisphere. Also Tasmania.

Lamproderma fuscatum Meylan (Bull. Soc. Vaud. Sc. Nat. 57 : 372,
1932), reported from Switzerland, seems very close to this species.
The description is as follows: Sporangia stalked, globose, 1 mm. in
diameter; peridium gray, with bluish or brownish reflections, fragile,
breaking up into fragments; stipe shorter than the sporangium; cap-
illitium dense, grayish brown; spores dark ferruginous in mass, pale
by transmitted light, papillate, 9-11 fx. Plasmodium unknown.

10. Lamproderma sauteri Rost.

Mon. 205. 1875.
PI. XIII, Figs. 320, 321.

1892. Lamproderma robusta Ellis & Everh., in Massee, Mon. 99.

1894. Lamproderma violaceum (Fr.) Rost. var. sauteri List., Mycetozoa 129.

Sporangia globose or slightly depressed, usually flattened or um-
bilicate below, 1-2 mm. in diameter, stipitate, stipe usually short,
rarely exceeding the height of the sporangium; peridium membranous,
persistent, dark blue, not brilliant; capillitium purplish, coarse, with
pale tips, appearing hoary after the spores are shed; spores dark
purplish brown, spinulose, 12-15 fx.

A large, dark species, varying considerably in shape of sporangium

198 THE MYXOMYCETES

and in color. We here include American collections formerly referred
to L. robustum (L. sauteri var. robustum Graff, Mycologia 20 : 106,
1928). Differing from L. violaceum, of which the English monograph
regards both sauteri and carestice as varieties, in the larger, darker and
more distinctly spinulose spores, and in the much more robust spo-
rangia. A mountain species, the plasmodium developing beneath the
snow, according to Professor Meylan.

Forms with a slender stalk, slightly exceeding the height of the
sporangium have been called var. gracile Meylan; others, in which
the sporangium is top-shaped, var. turbinatum Meylan. The var.
pulchrum Meylan has spores 15-18 /x, a shining, metallic peridium and
a denser and darker capillitium; the var. atro-griseum Meylan has
equally large spores but a dull, iron-gray peridium.

Colorado, Montana, Washington, Oregon, California; Europe.

The following three species, recently described by Professor Meylan,
seem to belong close to L. sauteri. For the benefit of students, the
descriptions are appended. All are known, thus far, only from
Switzerland.

Lamproderma splendens Meylan

Bull. Soc. Vaud. Sc. Nat. 57 : 44. 1929.

Sporangia stipitate, rarely sessile, subspherical, not umbilicate be-
low, 0.8-1 mm. in diameter, dark blue or bronze, with brilliant metal-
lic reflections, rarely violaceous cinereous or brilliant black; stipe
0.5-0.8 mm. in length; columella short, thick; capillitium of rather
coarse, sparsely branched threads in the lower half, densely branching
toward the surface, or sometimes densely branched throughout; spores
pale, indistinctly papillate, 9-11 /x. Plasmodium white.

Lamproderma ovoideum Meylan

Bull. Soc. Vaud. Sc. Nat. 57 : 373. 1932.

Sporangia stipitate, ovate, 1.5-2 mm. in height, 1-1.5 mm. broad,
dark blue, sometimes bronze, shining, especially above; stipe less than
half the height of the sporangium; capillitium dense, dark brownish
purple; spores dark, papillate, 13-15 /x. Plasmodium white.

The var. piriforme Meylan, formerly regarded by its author as a
variety of L. sauteri, has a dark, shining, but not iridescent, peridium,
an obovate sporangium and very dark spores, 15-18 /x. The var.
cucumer Meylan is characterized by a cucumber-shaped sporangium,
grayish capillitium and smaller, paler spores, 10-13 fx.

LAMPRODERMA 199

Lamproderma pulchellum Meylan

Bull. Soc. Vaud. Sc. Nat. 57 : 369. 1932.

Sporangia sessile, globose, dark violet-blue with few reflections, 0.5-
1 mm. in diameter; columella short, sometimes almost lacking, attain-
ing at most one-third the height of the sporangium; capillitium densely
branched, pale rose; spores brownish purple, minutely papillose, 12-
14 jLt. Plasmodium unknown.

The sporangia appear in characteristic lines on the stems of grasses.

11. Lamproderma arcyrionema Rost.

Mon. 208. 1875.
PL XIII, Figs. 322, 323.

1893. Comatricha shimekiana Macbr., Bull. Lab. Nat. Hist. Iowa 2 : 380.

Sporangia gregarious, scattered, globose, silvery gray or bronze,
iridescent, erect, stipitate; stipe black, long, two-thirds to three-
fourths the total height, slender, rigid; columella slender, cylindric,
attaining about one-third the height of the sporangium when it breaks
into the primary branches of the capillitium; capillitium exceedingly
intricate, made up of slender, flexuous brown threads which frequently
branch and anastomose to form an elegant round-meshed network
resembling that of Arcyria, free ultimate branchlets not numerous;
spores in mass jet-black, by transmitted light violaceous, very faintly
warted, 6-8 /jl.

This species is easily recognizable by its very peculiar capillitium.
This, in its primary branching, resembles a comatricha. In typical
forms, the columella branches at the apex only, generally into two
strong divisions which then break up irregularly and anastomose in ev-
ery direction. This seems to have been the form present to Rostafinski
when he wrote "columella truncate." In Central American and some
North American specimens, the branching is very different; the twigs
leave the columella at various points almost down to the annulus,
and the entire effect is dendroid. The columella is lost almost at once.
A small form of this species was formerly distributed in the United
States as Comatricha friesiana Rost. This circumstance led the senior
author to describe Central American forms as C. shimekiana. Judg-
ing from a remark by Massee (Mon. p. 97), a similar confusion seems
to have prevailed in Europe. As a matter of fact, the resemblance be-
tween C. friesiana (i. e., C. nigra), and the present species is suffi-
ciently remote.

Lamproderma minutum Rostafinski may be a small form of this
species. Rostafinski bases his diagnosis upon the branching of the

200 THE MYXOMYCETES

columella, which is, as we have seen, inconstant, and upon the colorless
capillitium. This feature in specimens examined is also inconstant.

Occurring in large colonies on barkless decaying logs of various
species; the plasmodium almost colorless.

Common. Canada to Nicaragua, Puerto Rico, Brazil; Europe,
Asia, Africa.

12. Lamproderma scintillans {Berk. & Br.) Morgan

Jour. Cin. Soc. Nat. Hist. 16 : 131. 1894.
PL XIII, Figs. 324, 325.

1877. Stemonitis scintillans Berk. & Br., Jour. Linn. Soc. 15 : 84.

1877. Lamproderma arcyrioides (Somm.) Rost. var. iridea Cooke, Myx. G. B.

50.
1892. Lamproderma irideum Massee, Mon. 95.

Sporangia gregarious, scattered, globose or depressed-globose, 0.3-
0.5 mm. in diameter, metallic blue-purple or bronze, iridescent, stip-
itate; the stipe long, slender, even, inclined and nodding or sometimes
erect; hypothallus small, circular; columella cylindric, small, not reach-
ing the center, black; capillitium dense, of rigid, straight, sparingly
branched or anastomosing brown threads, which are typically white
or colorless just as they leave the columella; spores globose, rough,
violaceous brown, 7-9 ju.

The capillitium is remarkable, and constitutes an easy diagnostic
mark. The threads appear at first sight entirely simple, but are really
several times furcate, and not infrequently anastomose. The spores
are covered with sparsely sown large papillae, easily seen under
moderate magnification.

This is one of our earliest species. To be sought in May on beds of
decaying oak leaves in the woods, especially in wet places, near
streams, etc.

Not common in North America. Reported from New England,
Pennsylvania, Ohio, Iowa, Bolivia; Rumania, Ceylon, Japan.

13. Lamproderma physaroides {Alb. & Schw.) Rost.

Mon. 202. 1875.
1805. Stemonitis physaroides Alb. & Schw., Consp. Fung. 103.

Sporangia gregarious, wide-spreading, globose, the peridium persist-
ent with a silver metallic, sometimes brassy luster; stipe long, rather
thick, brown or black, tapering upward; hypothallus well developed,
brown or purple, usually not continuous; columella swollen at tip,
obtuse, short at best, hardly attaining the center of the sporangium;

LAMPRODERMA 201

capillitium very rigid, of simple or sparingly branched, dark brown
threads radiating from the clavate apex of the columella and only here
and there anastomosing toward the surface, the ultimate divisions
distinctly rough; spores lilac-brown, rough, 10-12.5/1.

This species is well described in Rostafinski's Monograph. It is
marked by its clavate columella and peculiarly simple, dark, rigid
capillitium, the branches of which rise in great numbers immediately
from the columella, and maintain their primitive thickness during the
greater part of their length. The transverse vincula are often at right
angles to the principal branches, and the meshes, where formed, are
often long and rectangular. Externally, it resembles L. arcyrionema,
but is by its spores and capillitium instantly distinguished. Rostafinski
gives the spore-size as 12.5-14.2 /x. Large spores are less common in
the specimens before us.

In the third edition of the English monograph this species is doubt-
fully included in L. columbinum.

In the first edition of North American Slime-Moulds, this species
was entered from lists published for New England, New York and
Ohio. The intervening years, however, have brought no confirmation.
Specimens from Maine and Ohio, with large spores, represent L.
columbinum, and those cited from New York are forms of L. violaceum.
It is accordingly doubtful whether L. physaroides occurs in North
America. That it is to be found in Europe there seems no doubt. The
figure and description of Schweinitz may indeed be inconclusive, but
Rostafinski's citation and abundant description leave no doubt as to
his opinion; while numerous localities named would indicate adequate
material. What Rostafinski described will no doubt obtain wider
recognition some day.

14. Lamproderma columbinum (Pers.) Rost.

Mon. 203. 1875.

(as L. columbina)

PI. XIII, Figs. 326, 327.

1795. Physarum columbinum Pers., Ust. Ann. Bot. 15 : 5.
1808. Trichia columbina (Pers.) Poiret, Lam. Encycl. 8 : 52.
1836. Fulgia encaustica Chev., Fl. Par. ed. 2. 347.

Sporangia scattered, gregarious, rich violet or purple with metallic
iridescence, globose, stipitate; stipe long, three-fourths the total
height, subulate, black; hypothallus scant, purplish or brown; colu-
mella small, one-third the height or less, tapering or acute, black;
capillitium brown throughout, not dense, arising from nearly all parts
of the columella, freely branching and anastomosing to an open,

202 THE MYXOMYCETES

large-meshed network; spore-mass black; spores by transmitted light
smoky brown, rough, 11-14 jj,. Plasmodium white, rarely yellow.

Rostafinski distinguished this beautiful species by the color of the
peridium and the conic columella. According to Mr. Lister, Rostafin-
ski was not sufficiently careful in labelling his material, different forms
having been included under this specific name. Nevertheless, the
description is well drawn, and excludes L. physaroides completely. At
all events our American specimens correspond so well with the de-
scription of L. columbinum (Pers.) Rost. that there seems no doubt
that we have here what the Polish author figured and described,
whether or not he was always consistent in applying his labels. The
color distinguishes at sight the present species from L. physaroides,
and the capillitium and large rough brown spores distinguish it from
L. violaceum. The capillitium of the minute L. scintillans is much
denser and more rigid, and the spores smaller. The stipe when dry is
ciliate.

This is the common species of our western mountains, especially on
the Pacific slope. In the Cascades every dark ravine is certain to show
it in later summer and autumn, far extended colonies covering the moist
surfaces of every moldering log, the myriad globoid sporangia giving
back when brought to the sunlight the most extravagant blues and
greens with all the splendor of metallic sheen. Their brilliant beauty
never fails to quicken the attention of even the most insensate tourist.

The English monograph recognizes the varieties gracile G. List.,
with elongated oval sporangia; iridescens G. List. (= Physarum
iridescens Berk., Hooker Jour. Bot. 3 : 20, 1851; L. iridescens (Berk.)
Rost., Mon. App. 25, 1876), with spherical sporangia and pale, lax
capillitium, and brevipes G. List., with dull, flattened sporangia and
very short stalks. Meylan (Bull. Soc. Vaud. Sc. Nat. 56 : 322, 1927)
believes brevipes a distinct species, and in the same publication raises
his former variety subglobosum to specific rank as L. subglobosum. This
has a slightly flattened sporangium, like brevipes, but a long stalk and
a short columella. L. cruchetii Meylan is not regarded by Miss Lister
as worthy even of varietal recognition. According to Meylan it has a
yellow Plasmodium requiring two or three weeks to form sporangia,
while that of L. columbinum is white and forms sporangia in two to
four days after emergence. There are other differences cited, such as
the proportionately shorter stem of cruchetii, its somewhat simpler
capillitium, and its somewhat larger, often greenish brown spores.
These forms are as yet known only from the Swiss mountains, but will
doubtless appear elsewhere.

Abundant in the western forests, extremely rare in the eastern

CRIBRARIACE.E 203

United States. British Columbia, Washington, Oregon, Montana,
Maine, Pennsylvania, South Carolina; Europe, Tasmania.

Order LICEALES
True capillitium none or rarely scantily developed (except in genus
Alwisia) ; pseudocapillitium present or absent, when present, of tubules
or perforated plates which sometimes fray out into threads; spores
pallid or brown, rarely dark.

KEY TO FAMILIES OF LICEALES

a. Sporangium wall membranous, often falling away between net-
like thickenings; sporangium and spores clotted with plasmodic

granules Cribrariacejs

a. Sporangial wall not netted; plasmodic granules lacking b

b. Sporangia separate, sometimes more or less plasmodio-

carpous Liceace^e

b. Sporangia densely massed, usually forming a pseudo-

aethalium; or fructification a true aethalium c

c. Sporangia closely appressed, but with walls entire; individual

sporangia dehiscent at apex Tubiferace^;

c. Fructification either a true asthalium or a pseudo-aethalium in
which the sporangial walls disappear at maturity; dehiscence

typically irregular "

d. Pseudocapillitium thread-like or of perforated, frayed or

fragmentary plates; spores ochraceous or umber ReticulariacEjE

d. Pseudocapillitium of colorless branched tubes; spores

pinkish or pallid Lycogalace*:

Family CRIBRARIACE.E

Sporangium wall membranous, dotted with microscopic plasmodic
granules; continuous or more typically with net-like thickenings in the
upper portion, the remainder fugacious; capillitium entirely absent.

The distinctive character of this family is to be found in conspicuous
dark granules found both in the plasmodium and in the fructifications.
The place of capillitium is taken, except in Lindbladia, by the net-like
thickenings of the peridium wall, left when the thinner portions of the
wall disappear, and serving to hold the spherical central mass of
spores while permitting their gradual liberation. The plasmodium is
often brilliantly colored— violet, purple, blue, green, brown or black.
The species occur more commonly on coniferous wood.

KEY TO THE GENERA OF THE CRIBRARIACE^

a. iEthalioid, the net lacking 1. Lindbladia

a. Sporangia separate, stalked or very rarely sessile; net present b

b. Main threads of net short, connected by numerous expanded

no d es 2. Cribraria

b. Main threads of net parallel, extending from base to apex, con-
nected by delicate filaments 3. Dictydium

204 THE MYXOMYCETES

1. Lindbladia Fries
Summa Veg. Scand. 449. 1849.

Fructification aethalioid; the sporangia short, tubular, sometimes
superimposed, sometimes forming a simple stratum, in the latter case
generally sessile, but sometimes short-stipitate, the peridium at first
entire, at length opening irregularly either at the sides or apex, beset
with granules; spores olivaceous.

This genus was established by Fries in 1849 to accommodate a single
species of wide distribution and somewhat varying habit, which is
neither a tubifera nor yet a cribraria but offers points of resemblance
to each. It resembles Tubifera in its simple sporangia, opening without
the aid of a net; it is like certain species of Cribraria in the smooth
ochraceous-olivaceous spores and is allied to that genus by its gran-
uliferous peridium.

Lindbladia effusa {Ehr) RosL

Mon. 223. 1875.
PI. XIII, Figs. 328, 329.

1818. Licea effusa Ehr., Sylv. Myc. Ber. 26.

1849. Lindbladia tubulina Fr., Summ. Veg. Scand. 449.

1851. ALthalium atrum Preuss, Linnaea 24 : 141.

1854. Reticularia maxima Corda, Icon. 6 : 14, pi. 2, fig. 35.

1892. Tubulina effusa (Ehr.) Massee, Mon. 41.

Sporangia minute, either closely combined and superimposed, so as
to form a pulvinate aethalium, or crowded together in a single layer,
sessile or short-stipitate; the peridia thin, membranous, marked by
scattered plasmodic granules, often lustrous, sometimes dull lead
colored or blackish, especially above; stipe, when present, very short
but distinct, brown, rugulose; hypothallus well developed, membra-
nous, or more or less spongy in structure; spore-mass ochraceous; spores
under the lens nearly smooth, almost colorless, 6-7.5 fx. Plasmodium
brownish black.

This very variable species has been well studied by Dr. Rex. See
Bot. Gaz. 17 : 201. In its simpler phases it presents but a single layer
of sporangia generally closely crowded together, sometimes free and
even short-stipitate! In the more complex phase the sporangia are
heaped together in a pulvinate mass in which the peridia appear as
boundaries of minute cells. In this case the outermost sporangia are
often consolidated to form a cortex more or less dense and shining.
In any case the hypothallus is a prominent feature; generally lami-
nated and of two or three layers, it is in the more hemispheric aethalia

CRIBRARIA 205

very much more complex, sponge-like. When thin this structure is
remarkable for its wide extent, 40-50 cm. ! The simpler forms approach
very near to Cribraria through C. argillacea. The most complex re-
mind us of Enteridium.

Var. simplex Rex, Bot. Gazette 17 : 202, 1892 (= Licea spermoides
Berk. & Curt., Grev. 2 : 68, 1873; Physarum ccespitosum Peck, Rept.
N. Y. Mus. 26 : 75, 1874; Perichcena ccespitosa Peck, Rept. N. Y.
Mus. 31 : 57, 1889; Tubulina spermoides (B. & C.) Massee, Mon. 37,
1892; Tubulina ccespitosa (Peck) Massee, Mon. 43, 1892) is sometimes
used for the phase in which the sporangia are more or less separate,
cylindrical, even stalked, approaching Cribraria argillacea.

Ehrenberg throws some doubt on the species he describes by sug-
gesting that the Plasmodium may be red. The description, however,
and figures are otherwise good. The Plasmodium has much the same
color as the mature fruit.

Widely distributed. New England to the Black Hills and Colorado,
south to Arkansas and west to Washington and California; northern
temperate regions, Ceylon.

2. Cribraria Persoon emend. Rost.

Mon. 231. 1875.

1794. Cribraria Pers., Roemer N. Mag. Bot. 1 : 91, in part.
1797. Cribraria Schrader, Nov. Gen. Plant. 1.

Sporangia distinct, gregarious or closely crowded, globose or obo-
void, stipitate or rarely sessile; the stipe of varying length; the peridium
simple, marked within by distinct and peculiar granular thickenings,
which below take the form of radiating ribs, supporting the per-
sisting cup, the calyculus, and above, by extremely delicate anas-
tomosing branches, united to weave a more or less regular net with
open polygonal meshes; spores various, most commonly yellowish or
ochraceous, sometimes brown, reddish or purple.

The genus Cribraria, as limited by Persoon, included all forms in
which the peridium is thin, evanescent at least in the upper half, and
in which the capillitium, as Persoon regarded it, is formed of a net-
work of reticulate threads surrounding the spores. Schrader redefined
the genus; opposed Persoon 's view as to the capillitial nature of the
net, and separated the genus Dictydium, but by imperfect limita-
tions, — in fact, chiefly because of the more completely evanescent
peridium. Fries follows Schrader. Rostafinski first clearly separated
the two genera, and his classification is here adopted. Nevertheless,
after reviewing the subject one is more and more inclined to appre-

206 THE MYXOMYCETES

date the commendation of Fries: "Auctor Schrader, qui insuper
plurimas species detexit, et hoc et sequens genus ita proposuit ut
sequentes vix aliquid addere valuerint."

As to the habitat of the cribrarias, the remark of Schrader — "in
vetustissimis plenariae destructioni proximis arborum truncis" — is
pertinent for all the species save one. Rotten coniferous wood seems
to be preferred, but frondose wood is by no means refused. Rotten
oak forms a not infrequent substratum.

The major part of the following key and a considerable part of the
treatment of the species is based on the work of Miss Eunice Lovejoy,
presented as a thesis at the University of Iowa in 1931.

KEY TO THE SPECIES OF CRIBRARIA

a. Net obscure, fugacious; sporangia sessile or short-stipitate;

densely crowded 1. C. argillacea

a. Net persistent; sporangia stalked; gregarious or scattered b

b. Ochraceous or brown c

b. Orange, red or purple q

c. Caly cuius lacking, or, if present, very small or represented

by ribs. (See also Nos. 6, 14) d

c. Calyculus well developed. (See also Nos. 4, 5) g

d. Free ends lacking in net, or few e

d. Free ends usually numerous /

e. Moderately large, 0.3-0.7 mm. in diameter; nodes flat-
tened 2. C. splendens

e. Small, under 0.4 mm. in diameter; nodes thickened 3. C. microcarpa

f. Connecting threads of net single; granules ochra-
ceous 4. C. didydioides

/. Connecting threads often parallel in twos or threes;

granules dark brown 5. C. intricata

g. Nodes expanded h

g. Nodes thickened *

h. Net light ochraceous, meshes small, with no free ends . . 6. C. minutissima
h. Net dark brown, meshes large, with free ends 7. C. atrofusca

i. Nodes flat and angular j

i. Nodes rounded o

j. Sporangia small, under 0.4 mm k

j. Sporangia larger, over 0.5 mm tn

k. Copper colored; meshes large; nodular granules pale 8. C. cuprea

k. Dark brown, with dark granules I

I. Deep reddish brown; spores 5-6.5 n 9. C. languescens

I. Nearly black; spores 9/x 10. C. oregana

m. Spores reticulated 11. C. dictyospora

m. Spores spiny or roughened n

n. Dusky; margin of calyculus dentate; free ends few 12. C. piriformis

n. Yellow-brown; margin of calyculus perforated; free ends

numerous 13. C. macrocarpa

CRIBRARIA 207

o. Small, under 0.5 mm. in diameter; stipe 2-6 mm 14. C. tenella

o. Larger, 0.5 mm. or over; stipe 1-2 mm p

p. Yellow-brown; margin of calyculus dentate; on wood.. . 15. C. aurantiaca
p. Nut brown; calyculus prominently ribbed; on leaves. . . 16. C. laxa

q. Deep yellow, orange or red r

q. Purple, lavender or blue t

r. Reddish tawny; minute, 0.15-0.2 mm. in diameter 17. C. exigua

r. Deep yellow or orange; diameter 0.6-0.7 mm 18. C. rufa

r. Red; over 1 mm. in diameter 5

s. Ruby red; nodes expanded, not granular 19. C. rubiginosa

s. Brick-red; nodes scarcely expanded, granular 20. C. ferruginea

t. Nodes expanded u

t. Nodes thickened v

u. Net purple; nodular granules reddish purple 21. C. purpurea

u. Net dark blue; nodular granules black 22. C. lepida

v. Deep lilac or reddish purple, 0.4-0.5 mm. in diameter;

spores 5-6 y. 23. C. elegans

v. Violet, 0.2-0.3 mm. in diameter; spores 7-8 n 24. C. violacea

1. Cribraria argillacea Pers.

Roemer N. Mag. Bot. 1 : 91. 1794.
PI. XIII, Figs. 330, 331.

1791. Stemonitis argillacea Pers., in Gmel., Syst. Nat. 2 : 1469.
1797. Cribraria micropus Schrad., Nov. Gen. PI. 3, pi. 2, figs. 1, 2.
1808. Trichia argillacea (Pers.) Poiret, in Lam. Encycl. 8 : 55.

Sporangia dull ochraceous-olivaceous, globose, nearly 1 mm. in
diameter, sessile or short-stipitate, closely gregarious or crowded, the
peridial walls at maturity smooth, shining, except above, long-per-
sistent, obscurely reticulate, with irregular thickenings which at the
apex at length present the appearance of an irregular, coarsely meshed
net without nodal thickenings; hypothallus silvery, evanescent; stipe,
when present, very short, stout, erect, reddish brown; spore-mass
ochraceous; spores by transmitted light pale yellow, spinulose, 5-7 /x.
Plasmodium lead colored, scanty.

In habit and form of sporangia suggesting Tubifera, but possessing
the reticulations and plasmodic granules of Cribraria. In freshly
formed sporangia the reticulations are barely visible in the crown;
later on they are more manifest, until, as spore dispersal proceeds, the
cribraria characters come out with sufficient distinctness, and in
empty sporangia the reticulations may be seen to affect the entire
peridial wall. The nodes are not expanded.

Not uncommon. New England, Ontario and Washington to South
Carolina, Iowa and Oregon. Widely distributed in temperate regions,
mainly on rotten coniferous wood; also reported from South Africa.

208 THE MYXOMYCETES

2. Cribraria splendens {Schrad.) Pers.

Syn. Meth. Fung. 191. 1801.
PI. XIV, Figs. 332, 333.

1797. Dictydium splendens Schrad., Nov. Gen. PI. 14, pi. 4, figs. 5, 6.
1808. Trichia splendens (Schrad.) Poir., in Lam. Encycl. 8 : 55.

Sporangia gregarious, globose, 0.3-0.7 mm. in diameter, yellow
when filled with spores, dull or dusky brown when these are dis-
charged, stipitate; stipe long, 3-4 times the sporangium, subulate,
erect-nodding, brown; hypothallus small; network brown, with large
meshes, imperfectly defined, flattened nodes and flattened threads;
calyculus none, its place supplied by nine or ten distinct, firm ribs
which radiate from the stipe and support the net, branching to blend
with its reticulations; spore-mass yellow; spores by transmitted light
colorless, smooth or nearly so, 6-7 ji. Plasmodium lead colored.

Differing from all other species in the peculiar ribs which take the
place of the calyculus. The color is a glistening yellow or brown.
The stipe displays a purple iridescence in bright sunlight; in duller
light it appears purplish brown.

Widely distributed, but rare. Nova Scotia, Ontario, New York,
Pennsylvania, Iowa, Wyoming, Washington, West Indies; Europe,
Malay Peninsula, Japan.

3. Cribraria microcarpa {Schrad.) Pers.

Syn. Meth. Fung. 190. 1801.
PI. XIV, Figs. 334, 335, 336.

1797. Dictydium microcarpum Schrad., Nov. Gen. PI. 13, pi. 4, figs. 3, 4.
1808. Trichia microcarpa (Schrad.) Poiret, in Lam. Encycl. 8 : 54.

Sporangia scattered, yellow ochraceous, globose, stipitate, nodding,
0.15-0.4 mm. in diameter; calyculus none, net arising directly from
the stipe, the meshes large, mostly rectangular, a few triangular;
nodes thickened, rounded, small, dark brown, granular; connecting
threads stout, transparent, free ends few or none; stipe dark purplish
brown, 0.5-1.5 mm. long, furrowed, slender, tapering upward; spore-
mass yellow, fading to ochraceous; spores by transmitted light pale,
minutely spinulose, 6-7 /jl. Plasmodium purplish black according to
Lister; in our experience colorless except as colored by material from
the substratum.

At first sight resembling C. tenella, but the sporangia are smaller,
the meshes of the net larger, the nodes smaller and fewer in number,
the stipe shorter, the calyculus lacking and the ribs few and simple.
In the Lister monograph the color is given as purplish red with the

CRIBRARIA 209

spores pale red in mass. Schrader's original description calls for a
brown form with yellow spores, which is in agreement with the speci-
mens examined. The entire fructification becomes purple, however,
when mounted in potassium hydroxide.

Not common. New England, Ontario, Pennsylvania, Ohio, Iowa,
Missouri, California; Europe, southern Asia, Japan.

4. Cribraria dictydioides Cooke &° Balf.

in Massee, Mon. 65. 1892.
PI. XIV, Figs. 340, 341, 342.

1894. Cribraria intricata Schrad., var. dictydioides (Cke. & Balf.) List., Myce-
tozoa 144.

Sporangia gregarious, dusky brown, globose, 0.5-0.7 mm. in di-
ameter, cernuous, stipitate; stipe long, slender, furrowed, tapering
upwards, dull brown in color; hypothallus small; calyculus rudimen-
tary or represented only by irregular, node-like ribs; network delicate,
the meshes small, few-sided; nodules large, prominent, brown, ir-
regular, with several radiating, free, projecting threads, beside the
single continuous filaments which pass from node to node; spore-
mass pale, ochraceous; spores nearly smooth, colorless, 5-7 ix.

This seems to be the most common Cribraria in the Mississippi
valley. It is generally distinguished by the lack of a calyculus and
the beautiful richness of its clear delicate net. The stellate nodules,
especially above, emit rays in all directions, but are, notwithstanding,
united by single, unpaired threads only. The rather large sporangia,
the nodes joined by single threads, the remaining radiant threads,
many or few, but very short — these seem to be the most distinctly
diagnostic characters, and these are sufficiently constant to separate
this species easily from C. intricata on the one hand and C. tenella on
the other.

Abundant on rotten logs of every sort, especially oak. New York
and Ontario to Wisconsin, North Carolina and Nebraska, Washington;
Europe, West Africa, southern and eastern Asia.

5. Cribraria intricata Schrad.

Nov. Gen. PI. 7, pi. 3, fig. 1. 1797.
PL XIV, Figs. 337, 338, 339.

1808. Trichia intricata (Schrad.) Poiret, in Lam. Encycl. 8 : 56.

Sporangia gregarious, globose, large, 0.6-1 mm. in diameter, nut-
brown or olivaceous, erect or nodding, stipitate; stipe long, 1.5-3 mm.,

210 THE MYXOMYCETES

dark brown, furrowed, slender, flexuous, tapering upward; calyculus
lacking, its place taken by reddish brown, granular ribs; net prominent,
meshes of medium size, usually triangular; nodes thickened, large,
irregular, reddish brown, granular, giving rise to many long free ends;
connecting threads parallel, often two or three together; hypothallus
conspicuous; spores ochraceous in mass, by transmitted light pale,
spiny, 6-7 /*.

Distinguished by the parallel connecting threads, agreeing in this
respect with Rostafmski's fig. 27, pi. 2, and Massee's fig. 11, pi. 1.
Lister regards C. dictydioides as merely a variety of this species. The
latter, however, has short free ends and nodes of a lighter color. C.
tenella also resembles it in shape and size of the sporangium but is
provided with a calyculus and lacks the long free ends and parallel
connecting threads.

Rare. New England, Pennsylvania, Iowa, Missouri, West Indies,
Bolivia; Europe, South Africa, Ceylon, Malay Peninsula, Japan.

6. Cribraria minutissima Schw.

Trans. Am. Phil. Soc. II. 4 : 260. 1832.
PI. XIV, Figs. 343, 344, 345.

1873. Cribraria minima Berk. & Curt., Grev. 2 : 67.
1873. Cribraria microscopica Berk. & Curt., Grev. 2 : 67.

Sporangia minute, scattered, nut-brown, 0.1-0.3 mm. in diameter,
erect; calyculus variable, when fully mature separated from the net
by a shallow constriction; more commonly the constriction is not
present, and the cup may be entirely lacking; nodes expanded but not
thickened, bearing light granules; connecting threads flattened, free
ends lacking, hypothallus none; stipe brown, one to three times the
height of the sporangium; spore-mass yellow; spores by transmitted
light pallid, minutely roughened, 5-7 fx.

In its typical expression this species is characterized by its minute
size and the wide-meshed net bulging from the calyculus. Often, how-
ever, the calyculus is partly or entirely suppressed. The sporangia
without calyculus, however, are usually scattered among others with
it, and are often smaller, suggesting incomplete development. They
have every appearance of having arisen from the same plasmodium.
C. minima and C. microscopica seem to stand for these forms with
and without the calyculus, respectively.

Rare, or at least seldom collected. New York, Pennsylvania, North
Carolina, South Carolina, Missouri, Iowa, South Dakota, Washing-
ton; Europe, southern Asia.

CRIBRARIA 211

7. Cribraria atrofusca Martin & Lovejoy

Jour. Wash. Acad. Sc. 22 : 92. 1932.
PL XV, Figs. 368, 369, 370.

Sporangia loosely gregarious, dark purplish brown to nearly black,
shining, iridescent, globose or somewhat obovate or occasionally pyri-
form, usually erect, 0.4-0.6 mm. in diameter, total height 1-2 mm.
or more; calyculus occupying nearly or quite one-half of spore-case,
marked by slender granular ribs radiating from the stipe and by broken
concentric granular thickenings deposited on the inside, the concen-
tric character being visible without under the lens in brilliant light,
the margin with very fine teeth and long, slender tooth-like projec-
tions which bear the net and are similar to its nodes; net regular,
with broad connecting threads, the nodes expanded, granular, dark
brown, with a few free ends arising from both nodes and threads, the
silvery peridium tending to persist; hypothallus small; stipe dark
brown or nearly black, slender, furrowed, 0.6-1.8 mm. long; spores
dark reddish brown in mass, grayish brown by transmitted light,
finally verrucose, 7.5-8.1 /z, averaging 7.9 fx.

A distinct species. The dark glistening sporangium, the dark spores,
and the granular concentric rings within the calyculus are diagnostic.
The tooth-like projections which bear the net are longer and more
slender than in any other species, but their structure suggests that
they are to be regarded as elements of the net rather than of the
calyculus. The peridium tends to be more persistent than in most
cribrarias and in its shining silvery character suggests Lamproderma
arcyrionema. The spores are much the color of those of the more
ferruginous species of Stemonitis.

Colorado.

8. Cribraria cuprea Morgan

Jour. Cin. Soc. Nat. Hist. 15 : 142. 1893.
PL XIV, Figs. 346, 347.

1925. Cribraria languescens Rex ex Lister, Mycetozoa ed. 3. 176, in part.

Sporangia gregarious, small, 0.3-0.4 mm., subglobose, copper col-
ored, stipitate, nodding; stipe concolorous or darker below, subulate,
curved at the apex, 2-4 times the diameter of sporangium; calyculus
one-third to one-half the sporangium, finely ribbed and granular
within, the margin nearly even; net rather rudimentary, the meshes
large, triangular or quadrilateral, the nodes also large, flat, concolorous,
thickened, the threads slender, transparent, with few free ends; spores
in mass copper colored, by transmitted light colorless, minutely
roughened, 6-7 fx.

212 THE MYXOMYCETES

Recognizable by its small size, deep calyculus and peculiar color,
that of bright copper, although this fades somewhat with age, and
the metallic tints are then lacking. Related to C. languescens and in
specimens having globular sporangia closely resembling it; but the
ground color in C. languescens is always darker, and in well-developed
specimens the stipe proportionally much longer. In habit the spo-
rangia ar