THE MYCETOZOA OF NORTH AMERICA HAGELSTEIN, MYCETOZOA PLATE 1 WOODLAND SCENES IZ THE MYCETOZOA OF NORTH AMERICA BASED UPON THE SPECIMENS IN THE HERBARIUM OF THE NEW YORK BOTANICAL GARDEN BY ROBERT HAGELSTEIN HONORARY CURATOR OF MYXOMYCETES ILLUSTRATED MINEOLA, NEW YORK PUBLISHED BY THE AUTHOR 1944 COPYRIGHT, 1944, BY ROBERT HAGELSTEIN LANCASTER PRESS, INC., LANCASTER, PA. PRINTED IN U. S. A. To (^My CJriend JOSEPH HENRI RISPAUD CONTENTS PAGES Preface 1-2 The Mycetozoa (introduction to life history) .... 3-6 Glossary 7-8 Classification with families and genera 9-12 Descriptions of genera and species 13-271 Conclusion 273-274 Literature cited or consulted 275-289 Index to genera and species 291-299 Explanation of plates 301-306 PLATES Plate 1 (frontispiece) facing title page 2 (colored) facing page 62 3 (colored) facing page 160 4 (colored) facing page 172 5 (colored) facing page 218 Plates 6-16 (half-tone) at end ^^^56^^^ f^^ PREFACE In the Herbarium of the New York Botanical Garden are the large private collections of Mycetozoa made by the late J. B. Ellis, and the late Dr. W. C. Sturgis. These include many speci- mens collected by the earlier American students, Bilgram, Farlow, Fullmer, Harkness, Harvey, Langlois, Macbride, Morgan, Peck, Ravenel, Rex, Thaxter, Wingate, and others. There is much type and authentic material. There are also several thousand specimens received from later collectors, and found in many parts of the world. During the past twenty years my associates and I have collected and studied in the field more than ten thousand developments in eastern North America. The larger part and best of these have been placed in the Herbarium. The entire collection is large enough to enable one to form a proper idea of the distribution in North America; and the geographical records, as given, have been taken therefrom unless preceded by an asterisk. The latter refer to reports by other authors, and it is possible a few of them are erroneous, particularly in instances of single re- ports of rare or obscure forms. Reports of rare species, published by students who it is believed have had no access to authentic material to verify their determinations, have been ignored. The classification and division into families and genera follows that of Lister, which has been found more workable than others. The species within a genus are arranged, generally, in the order of their affinities, which assists in locating a species. The keys occasionally depart from this order when more prominent charac- ters are used. Complete lists of synonyms are not given. They may be found in the monographs of Lister, and of Macbride, and it is unnecessary to repeat them. The colors of the spores are given throughout as they are seen in the microscope by trans- mitted light when separated, and with magnifications of 600 to 800 diameters. The following words are used after Herbarium numbers to designate important specimens. Type or cotype: the particular specimen used for the original description. Type or cot^'pe material: material distributed by an author as part of the type or 1 2 Mycetozoa of North America cotype. Authentic material : material determined and distributed by the author as typical of the form described. My thanks are due to Miss G. Lister who, has extended her kindly aid on many occasions. Also, to Mr. John D. Thomas and Mr. Leon J. Chabot, who have accompanied me on many col- lecting excursions; and to the many friends who have helped by sending rare and unusual forms. The work of editing and proof- reading has been done by Dr. John Hendley Barnhart, Bib- liographer Emeritus of the New York Botanical Garden, to whom I am greatly indebted. Mr. Joseph H. Rispaud, my constant companion in the field, is part and parcel of this book. His wide field experience, and indefatigable collecting activities, have made possible the major portion of the material on which it is based. My gratitude to him cannot be expressed in words. Robert Hagelstein MiNEOLA, New York April 27, 1944 THE MYCETOZOA INTRODUCTION The Mycetozoa, Myxomycetes, or Slime-Molds, as they are variously named, are an interesting group of organisms that have both animal and vegetable characteristics, yet are not definitely intermediate. They produce fruiting bodies with spores, which resemble certain fungous growths, and the formative processes of these bodies are similar to those of some of the fungi. The spores when wetted, however, germinate into small amoeboid bodies which develop flagella, move, feed, and multiply by division, and are regarded by zoologists as Protozoa. After some transforma- tions, they fuse in great numbers into a mass of naked protoplasm, with many nuclei, called the plasmodium. The plasmodium moves by extending pseudopodia in the direction of its movement, feeds on bacteria and other organic material, and increases in size by the division of the nuclei. It may grow to a size of several feet across, functions somewhat like a giant amoeba, and is re- garded by many as an animal. The plasmodia vary in color and size in different species, and are sometimes confined to a particular habitat; otherwise, there is no way of differentiating between various plasmodia. This vegetative phase, as it is called, may continue for weeks or months, until the time arrives—depending on several factors—when the plasmodium must go into fruit in order to perpetuate the organism. It then emerges from its habitat (wood or ground) and by changes which closely resemble fungous processes produces fruiting bodies which simulate vege- table growths, but which perform no further living functions, and are dead except for the germ of life contained in each individual spore. The process occurs usually at night, and in the morning the area close to the last position of the plasmodium is covered by the sporangia or fruiting bodies, often in great numbers. The life cycle is then repeated through the germination of the spores. The unprotected plasmodium is delicate and subject to destruc- tion in dry or cold weather. Under such conditions, the mass may transform itself into a hard, brittle substance, known as sclerotium, which is inactive, but which will revive with warmth and water. In this condition, plasmodia will survive the winter months or other unfavorable periods. The fruiting bodies, excepting in one species which produces 3 4 Mycetozoa of North America sporophores, are of three kinds. (1) True sporangia, produced by the majority of the species, are often in thousands of indi- viduals from a single plasmodium, and are almost symmetrical and uniform in shape and size. Most of them are small, averag- ing in height about 1 mm., but in some species they may reach 15 to 25 mm. They may be sessile, or on stalks of varying height, and exhibit great diversity in form, color, and structure, among the different species. (2) Plasmodiocarps, produced habitually by certain species, and frequently by others that nor- mally produce true sporangia, are sporangiate in character, par- ticularly in their internal structure, but are not uniform in shape or size. The form may be extended in the linear direction many times the height or breadth, and again curved, serpentine, ring- or crescent-shaped. The form may be in thinly or thickly effused masses, or there may be a netted structure with numerous meshes or openings. In the latter formations the plasmodiocarps may extend several inches. Plasmodiocarps usually are sessile; are frequently produced in considerable numbers by an individual Plasmodium; and occur often along with true sporangia in the same fructification. (3) Aethalia. Here the entire mass of Plasmodium forms one or a small number of fruiting bodies. Aethalia are much larger, as a rule, than sporangia or plasmodio- carps, and in some species a single one may be as much as a foot across. The aethalium consists of confluent sporangia, the inter- vening walls more or less developed or degenerate, and the whole covered by a firm or fragile cortex or wall. The Mycetozoa require for their development a habitat of decaying vegetable material with warmth and moisture and the consequent growth of bacteria as a food supply. The plasmodia thrive in decaying wood (preferably in the earlier stages of decay), leaves, twigs, refuse and manure piles, and the ground, wherever favorable conditions prevail, and travel through the crevices and cavities in the search for food. The fructifications are produced on the habitat or in close proximity thereto. The time for their most prolific development in the northern temperate zone is in the months from June to October inclusive, although they may often be found in the other months, including those of the winter, if weather conditions are propitious. The appearances are not so abundant during long periods of wet or dry weather, but in the first week or so of dry weather, after a rainy speli,^ they may be expected plentifully. They may be sought for in- the most un- Introduction 5 usual places, but more successfully in places well suited for their development and with much habitat material. Such localities are secluded forest-areas with large trees of different kinds. There should be many fallen trees and logs in various stages of decay, with undergrowth and bushes to provide shade. The situation should be moist, either by the natural topography of the land and drainage, or by the presence of brooks, lakes, or springs. Localities suitable for mushrooms and other fungi are also fit for the Mycetozoa. It is surprising how many species may be found in a small area if repeatedly visited and intensively searched, and it is not unusual to collect fifty or more species in a single day.