Taxonomic Keys and Plates from The Myxomycetes Book by George W. Martin and Constantine J. Alexopoulos Digital work, reproduction of text and layout by Carlos Rojas & Carlos Lado Taxonomic Keys and Plates from The Myxomycetes Digital work, reproduction of text and layout by Carlos Rojas & Carlos Lado 2021 A project sponsored by 0 The material included herein is from The Myxomycetes, by George W. Martin and Constantine J. Alexopoulos (Illustrations by Ruth McVaugh Allen) © 1969. The University of Iowa Press. Reproduced with permission of The University of Iowa Press About this document In 1969, George W. Martin and Constantine J. Alexopoulos published a remarkable work on myxomycetes. Their monograph on this group of organisms became one of the references to the taxonomy and geographical distribution of the species in the world. The impact of this book was large, partially because they reviewed the previous works of Thomas Macbride (a large number of collections observed by Martin & Alexopoulos were collected by the former) and Arthur and Gulielma Lister (who sent European collections to the United States National Herbarium). In this manner, The Myxomycetes by Martin & Alexopoulos was in some ways, an update of the information already published in the books North American Slime-Moulds by Thomas Macbride (1922) and Monograph of the Mycetozoa by Arthur Lister (first edition in 1894). The original Martin & Alexopoulos The Myxomycetes book is found today in bookshelves of myxomycete researchers and institutional libraries around the world. It is the last worldwide monograph on myxomycetes. Despite being widely used for research purposes, the book has been out of print for many years and the younger generation of people interested in the fascinating world of myxomycetes has limited access to it. Both Macbride´s and Lister´s books have been rescued by the Biodiversity Heritage Library and can be accessed in digital format today, but The Myxomycetes by Martin & Alexopoulos is not available on the internet yet. Aware of that limitation, we obtained permission from the original publisher (University of Iowa Press) to create a digital version of the taxonomic keys and original plates contained in the book. Even though molecular techniques of myxomycete detection have been reshaping the nomenclature of the group in recent years and a number of binomials have changed over time, the original work published more than 50 years ago still offers important clues for taxonomic purposes. The drawings are much less detailed than those in Lister´s book, for example, but they are still useful for identification. However, they keys are comprehensive, detailed, and easy to use. We hope this digital compilation would contribute, even a little, to increase the access to scientific information in regions of the world where the original book has been difficult to read. We know it is not the same as having the actual book in your hands, but it is pretty close. Carlos Rojas Carlos Lado San José, Costa Rica Madrid, España April 5, 2021 How to use it This digital compilation was created with two types of embedded links. When the scientific names in the keys are clicked on, they link to the original plate where the illustration of the species is. When the figures on the plates are clicked on, they link back to the key, in the approximate position of the species name. The numbers after the scientific name in the keys, correspond to the drawing number and species in the respective plates. After each plate, there is one page showing the legends associated with it. We highly recommend checking the scientific names with the current nomenclatural treatments (visit https://eumycetozoa.com/). A number of names have been updated since the publication of the book. In this guide, the current accepted names (at any level) have been annotated within square brackets [ ] after the original species name. Acknowledgements You have access to the information in this document thanks to several people and institutions who were responsible for making it possible. Among these, we would like to recognize The University of Iowa Press for granting us permission to reproduce the material contained herein. The institutional support was facilitated by the Finca Experimental Interdisciplinaria de Modelos Agroecológicos from Universidad de Costa Rica (project 570- B9-7B4) and the Ministerio de Ciencia e Innovación de España (grant PGC2018-094660-B- I00). This document is a direct product of the Myxotropic Project (www.myxotropic.org) and the 10th International Congress on the Systematics and Ecology of Myxomycetes (ICSEM 10) held in Turrialba, Costa Rica. We express our gratitude to Carlos de Mier for the front cover image. Taxonomic Keys Taxonomic Index Class Myxomycetes Subclass Ceratiomyxomycetidae Order Ceratiomyxales Family Ceratiomyxaceae Genus Ceratiomyxa Subclass Myxogastromycetidae Order Liceales [Cribrariales] Family Liceaceae Genus Licea Family Reticulariaceae Genus Tubifera Genus Dictydiaethalium Genus Lycogala Genus Reticularia Family Cribrariaceae Genus Cribraria Genus Lindbladia Genus Dictydium Order Echinosteliales Family Echinosteliaceae Genus Echinostelium Order Trichiales Family Dianemaceae [Dianemataceae] Genus Listerella Genus Calomyxa Genus Minakatella Genus Dianema Family Trichiaceae Genus Perichaena Genus Oligonema Genus Calonema Genus Arcyria Genus Arcyodes Genus Cornuvia Genus Metatrichia Genus Prototrichia Order Stemonitales [Stemonitidales] Family Stemonitaceae [Stemonitidaceae] Genus Brefeldia Genus Amaurochaete Genus Elaeomyxa Genus Diachea Genus Schenella Genus Colloderma Genus Leptoderma Genus Diacheopsis Genus Enerthenema Genus Stemonitis Genus Clastoderma Genus Barbeyella Genus Macbrideola Genus Lamproderma Genus Comatricha Order Physarales Family Physaraceae Genus Cienkowskia [Willkommlangea] Genus Leocarpus Genus Physarella Genus Badhamia Genus Fuligo Genus Erionema Genus Craterium Genus Physarum Family Didymiaceae Genus Wilczekia Genus Physarina Genus Diderma Genus Mucilago Genus Didymium Genus Lepidoderma Genus Trichia Genus Hemitrichia CLASS MYXOMYCETES a. Spores borne externally on individual stalks, each producing on germination a naked protoplast which develops into a cluster of eight swarm-cells; hypothallus always well developed, giving rise to erect, often branched, and sometimes anastomosing extensions, the sporophores…………………..............….Subclass CERATIOMYXOMYCETIDAE (Ceratiomyxa) a. Spores borne internally in fructifications of characteristic form, each producing on germination one or two, rarely more, swarm-cells or myxamoebae; hypothallus occasionally prominent, usually inconspicuous, sometimes imperceptible……………………………………………Subclass MYXOGASTROMYCETIDAE (b) b. Spores in mass pallid or bright-colored, by transmitted light colorless to tinted or yellow-brown, less commonly dull black in mass and then smoky by transmitted light, never purple-brown; lime rarely secreted and then deposited on surface only………………………………………………………………………………………..……..c b. Spores in mass usually black or dark purplish brown, by transmitted light purple-brown or brown less commonly deep red, purple or ferruginous in mass, then often deeply tinted by transmitted light, rarely pale; lime, when present, secreted in characteristic fashion…………………………………………………………………………………………..e c. True capillitium lacking; pseudocapillitium, when present, of tubules or perforated plates which sometimes fray out into threads………………………………………………..Order Liceales c. True capillitium typically present, rarely lacking, but columella then present (rarely lacking in Echinostelium)……………………………………………………………….…………………………d d. Stalked, minute, pale or bright-colored; columella usually present, sometimes giving rise to a capillitium in the form of a loose, open, often incomplete net; peridium delicate, very early fugacious; spores white, pinkish, yellow or ochraceous in mass……………………………………………………………………..Order Echinosteliales d. Stalked or sessile, usually relatively large; columella lacking; capillitium usually abundant, of sculptured threads; peridium usually firm, often persisting below, at least to a late stage, spores light-colored in mass, tinted or brightly colored by transmitted light…………………………………………………………………………......Order Trichiales e. Neither peridium nor capillitium calcareous; lime rarely present and then restricted to hypothallus, base of peridium, stalk or columella……………………………....Order Stemonitales e. Peridium or capillitium, or both, calcareous in normal developments………Order Physarales Index Subclass CERATIOMYXOMYCETIDAE Order Ceratiomyxales Genus Ceratiomyxa a. Fructifications usually large, often extensive, the spores borne on erect, simple, branched or fruticose extensions, or sometimes arising directly from a resupinate or porose crust; spores smooth, sometimes globose but predominantly oval or elliptical in outline, 10-13 X 6-7 m......................................................................................................................C. fruticulosa. (1) a. Fructifications small or minute; spores somewhat smaller. b. Fructifications scattered, each consisting of a basal stalk bearing a cluster of branches at the tip, or branches rarely sessile; spore-bearing spicules at tips of branches notably long; spores subglobose, minutely roughened, (6-)-7-9(-10) m …………………………………………………………………………....C. sphaerosperma (3) b. Fructifications solitary or scattered, resembling Morchella in shape; spicules at tips not notably elongated; spores oval or elliptical, smooth, 9-10 x 6-8 m …C. morchella (2) Subclass MYXOGASTROMYCETIDAE Order Liceales [Cribrariales] a. Fructification of small, often minute, sporangia, or small, simple or sparsely branched, rarely effused, plasmodiocarps; neither pseudocapillitium nor dictydine granules present; spores mostly dingy to blackish in mass, then smoky by transmitted light, sometimes bright-colored in mass, then tinted yellow or ochraceous by transmitted light……………………………..Liceaceae a. Fructifications sporangiate to aethalioid, often large and conspicuous; spores pallid to variously colored but never smoky……………………………………………………………………b b. Dictydine granules lacking; usually aethalioid or pseudoaethalioid, if plasmodiocarpous or sporangiate, portions of peridium not persisting as a preformed net; spores yellow-brown by transmitted light……………………………………Reticulariaceae b. Dictydine granules present; mostly sporangiate, rarely united into a pseudoaethalium or an aethalium; portions of peridium in sporangiate forms persisting as a pre-formed net; spores pallid, ochraceous, pinkish or purplish, rarely yellow-brown by transmitted light………………………………………………………………………………..Cribrariaceae Index Family Liceaceae [only Genus Licea] Genus Licea a. Fructifications sessile, sometimes with restricted base but never stalked………………….….b a. Fructifications typically stipitate, rarely sessile and then usually accompanied by stalked sporangia………………………………………………………………………………………………..q b. Dehiscence circumscissile by a preformed lid …………………………………………..c b. Dehiscence not circumscissile by a preformed lid ………………………………………..e c. Sporangia bright coppery brown, with prominent tubules on inner portion of lid ……………………………………………………………………………………. L. kleistobolus. (7) c. Sporangia dark, not coppery, without tubules on inner portion of lid …....................................d d. Sporangial wall dark gray or dingy black, gelatinous when moist, drying black and shrivelled; lid morphologically distinct ……………………………………… L. parasitica (10) d. Sporangial wall dark brown, becoming black, not gelatinous; lid represented by upper plate, not morphologically distinct from lateral plates …....................L. belmontiana e. Sporangia spindIe-shaped, erect, about twice as high as wide; peridium black, shining, 2- lobed by a vertical suture; spores bearing prominent fugacious spines …...............L. fimicola (6) [currently considered Kelleromyxa fimicola (Dearn. & Bisby) Eliasson] e. Sporangia not spindle-shaped, rarely higher than wide; spines or warts on spores not fugacious except in L. chelonoides …..........................................................................................f f. Predominantly plasmodiocarpous, often branched, netted or effused, but varying to pulvinate; robust, the plasmodiocarps sometimes attaining 10 mm or more in extent …...............................................................................................................L. variabilis (15) f. Predominantly sporangiate or sometimes forming simple or sparsely branched plasmodiocarps rarely exceeding 1.5 mm in length ……………………………………….g g. Dehiscence by a longitudinal, rarely forked, slit ………………………………………………….h g. Dehiscence not typically by a longitudinal slit ……………………………………………………j h. Sporangia yellow-brown, darker below, elongate, 0.2-1.5 mm long, laterally compressed, sometimes sinuous, arcuate or slightly branched, forming simple plasmodiocarps; dehiscence by a preformed slit ………………………………L. biforis (4) h. Sporangia not laterally compressed, rarely attaining 0.4 mm in length; dehiscence by a longitudinal but not obviously preformed slit …...............................................................i Index i. Sporangia pulvinate, depressed, sessile on a broad base and surrounded by a dark rim; peridium thin, yellow-brown, coated by a slimy layer impregnated with dark granular material, drying black …..........................................................................................................L. marginata i. Sporangia pulvinate on a broad but restricted base, not notably depressed, shining yellow- brown, without slime and not surrounded by a dark rim …......................................L. pumila (365) j. Peridium marked by prominent ridges dividing it into angular platelets; dehiscence by separation of platelets, especially above ….....................................................................k j. Ridges on peridium obscure or lacking; dehiscence usually irregular …..................... o k. Chestnut to bright brown, tardily becoming dark; spores pale yellow-brown, smooth or nearly so, 9-11 m .…………………………………………………………………………..... L. castanea (5) k. Dark brown to umber, quickly darkening; spores distinctly sculptured ……………...………... l l. Platelets small, numerous; spores gray by transmitted light, with a conspicuous pale area, 11-13 m ......................................................................................... L. testudinacea l. Platelets large, relatively few; spores not gray ………………………………………….. m m. Dull black, sessile on a restricted base; spores pale reddish by transmitted light, strongly warted, the warts somewhat fugacious, 15-18 m ............................................... L. chelonoides m. Dark brown, or, if black, then shining; spores minutely warted to nearly smooth, the warts not fugacious …... n n. Pulvinate on a broad base, umber to dark reddish brown; spores reddish brown to dull ochraceous in mass, sometimes paler on one side, 10-13 m ….......... L. minima (8) n. Pulvinate on a somewhat constricted base, dark purplish brown to blackish; spores dark olivaceous in mass, ochraceous under lens, not notably paler on one side, mostly 15-17 m (smaller in var. pygmaea) ………………………………………….... L. pusilla (12) o. Platelets present, but obscure, rarely visible except in microscopic mount; ridges obscure; peridium black, tuberculate, shining …………………………………………..... L. tuberculata (14) o. Platelets and ridges completely lacking; peridium not tuberculate nor shining ……………... p p. Sporangia bright yellow-brown at maturity, darkening only with age and deposition of material from substratum, mostly 0.1-0.3(-0.5) mm in diameter; spores 10-12 m ………………………………………………………………………….………L. tenera (13) p. Sporangia dark brown to dull black at maturity, very minute, mostly 0.08-0.15 mm in diameter; spores 8-10 m ……………………………………………………..L. punctiformis Index q. Sporangia urniform, usually operculate, 0.1-0.3 mm in diameter; stalk slender; total height 0.4-1 mm; spores 8-11 m ………………………………………………………….. L. operculata (9) q. Sporangia globose to ovate, never operculate; stalk stout …………………………………... r r. Sporangia mostly 0.1-0.3 mm in diameter, stalked or rarely sessile on a constricted base; total height up to 0.6 mm; peridium composed of obscure platelets, but not netted nor ridged; spores 11-13 m ...................................................... L. pedicellata (11) r. Sporangia larger, 0.3-0.4 mm in diameter; total height up to 1.5 mm; peridium covered with a network of thickened ridges, but not divided into platelets; spores 14-15 m....................................................................................................................... L. erecta Family Reticulariaceae a. Fructification sporangiate, sporangia clustered or united into a pseudoaethalium……………b a. Fructification a true aethalium………………………………………………………………………c b. Sporangiate or pseudoaethalioid with persistent sporangial walls; hypothallus massive, fibrous or spongy……………………………………………………………………….Tubifera b. Sporangia closely appressed into a pseudoaethalium; sporangial walls disappearing at maturity except for thickened strands at the angles which persist as pseudocapillitial threads depending from the lids; hypothallus not massive or spongy…...Dictydiaethalium c. Aethalium subglobose to conical or pulvinate, often on a restricted base; pseudocapillitium of colorless, branching tubes; spores pinkish, then pallid in mass………………………..Lycogala c. Aethalium pulvinate on a broad base; pseudocapillitium of frayed or perforated, membranes; spores brown, yellow or olivaceous in mass…………………………..…Reticularia Genus Tubifera a. Sporangia clustered in groups of 2-8 on a fibrous, branching hypothallus; pseudocapillitium composed of bristles arising from base and walls of sporangial cavity, sometimes lacking ………………………………………………………………………………... T. bombarda (16) [currently considered Alwisia bombarda Berk. & Broome] a. Sporangia in large, dense clusters, often connate and forming a pseudoaethalium, pseudocapillitium rarely present and then appearing like branches from a columella; hypothallus spongy, massive ……………………………………………………………………..... b Index b. Sporangia fusoid-cylindrical, mostly free, clustered on a stem-like hypothallus; spores appearing warted but showing a faint and coarse reticulation under oil …………………………………………………………………………..….... T. papillata (20) b. Sporangia cylindrical, densely clustered; spores clearly reticulate over most of surface ………………………………………………………………………………………..... c c. Pseudocapillitium present, columella-like, sometimes with branches which may reach the sporangium wall …......... T. casparyi (17) [currently considered Siphoptychium casparyi Rostaf.] c. Pseudocapillitium lacking ……………………………………………………………………........ d d. Hypothallus contracted, forming a short, thick stalk; spores under 6 m in diameter…………………………………………………………………….T. microsperma (19) d. Hypothallus expanded; spores 6-8 m in diameter ….…………….... T. ferruginosa (18) Genus Dictydiaethalium a. Spores banded-reticulate; pseudoaethalia olivaceous; peridial caps about 60 m in diameter ……………………………………………………………………………... D. dictyosporum a. Spores warted or spinulose; pseudoaethalia usually bright yellow-brown to umber, but sometimes olivaceous; peridial caps usually exceeding 100 m in diameter….D. plumbeum (21) Genus Lycogala a. Aethalia large, mostly 2-4 cm in extent, sometimes much larger; cortex hard, thick, brittle, nearly smooth or bearing minute, slightly darkened scale-like patches; pseudocapillitium robust, often exceeding 25 m in diameter …............................................................. L. flavofuscum (25) a. Aethalia rarely over 15 mm in diameter, often much smaller; cortex rather thin, fragile, usually bearing clearly defined scales or warts; pseudocapillitium rarely attaining 25 m in diameter, usually much smaller …............................................................................................................ b b. Aethalia conical or subcylindrical, taller than wide, usually 2 mm or less in diameter; cortex bearing prominent dark warts arranged in a more or less reticulate pattern……………………………………………………………………………L. conicum (22) b. Aethalia subglobose, not taller than wide except when compressed in clusters; cortex not markedly reticulate ……………………………………………………………….. c c. Pallid to yellow-brown, rarely blackish, mostly 3-12 mm in diameter; cortical scales neither strongly pustulate nor tessellate; pseudocapillitium strongly sculptured, 10-25 m in diameter; spores clearly reticulate, mostly 6-7 m in diameter …................................... L. epidendrum (23) Index c. Brownish ochraceous to dark brown or black, mostly 1-3 mm in diameter, rarely larger; cortical scales pulvinate, prominent, dark, at first pustulate, tending to become tessellate; pseudocapillitium not strongly sculptured, rarely exceeding 10 m in diameter; spores faintly reticulate to nearly smooth, mostly under 6 m in diameter …............................. L. exiguum (24) Genus Reticularia a. Pseudocapillitium dendroid, at least in major part ……………………………………………... b a. Pseudocapillitium of perforated plates, these often fraying out into threads, but not dendroid …................................................................................................................................ c b. Pseudocapillitium membranous but not perforated at base, fraying out into dendroid columns of flexuous threads; cortex silvery, persistent; aethalia often large, up to 9 cm or more in extent …............................................................................... R. lycoperdon (29) b. Pseudocapillitium composed entirely of dendroid columns; cortex thin, brittle, evanescent; aethalia rarely exceeding 2 cm in extent …........................ R. intermedia (26) c. Aethalia robust, mostly 1-3 cm in extent, sometimes smaller, often larger, up to 6 cm, and 1 cm thick; cortex firm, persistent, smooth or wrinkled, glossy brown; pseudocapillitium firm, forming a persistent network with large, rounded perforations …................... R. splendens (31) c. Aethalia usually smaller and thinner; pseudocapillitium more delicate, less persistent ……. d d. Cortex firm, persistent, not bullate ……………………………………………………….. e d. Cortex bullate, translucent, often evanescent …......................................................... f e. Aethalia pulvinate, rusty brown, small, rarely over 1.1 mm in diameter but often massed in clusters, approaching pseudoaethalia in appearance; spores free, coarsely reticulate …………………………………………………………………………........... R. lobata (28) e. Aethalia depressed, olivaceous, usually small but sometimes attaining 5 cm and then very thin; spores usually clustered, warted or spiny on free surfaces ….................... R. olivacea (30) f. Aethalia very small, 4 mm or less, ochraceous orange; pseudocapillitium scanty; spores yellow, warted, 13 m............................................................................. R. aurea f. Aethalia larger, up to 25 mm, red-brown or coppery; pseudocapillitium abundant; . spores brown, delicately reticulate, 6-8 m …............................................... R. jurana (27) Index Family Cribrariaceae a. Sporangia usually Closely aggregated on an extensive, often thick and spongy hypothallus, the walls often united or fused, forming a pseudoaethalium or an aethalium, rarely scattered; net lacking or scantily developed, and peridium rarely if ever dehiscent between meshes; dictydine granules few and concolorous with membranes………………Lindbladia tubulina (32) a. Sporangia usually free, aggregated or scattered; net always present, usually well-developed; hypothallus delicate; dictydine granules numerous, darker than spores………………………….b b. Threads of net short, meeting at thickened or expanded nodes………………..Cribraria b. Main threads of net stout, longitudinal, subparallel at least below, connected by very delicate transverse threads; peridium sometimes netted above…………………Dictydium Genus Cribraria a. Nodes distinctly pulvinate to hemispherical when viewed laterally ……………………...…… b a. Nodes flat or only slightly thickened and then usually expanded, scarcely pulvinate ………. l b. Lilac, rose-red or purple ………………………………………………………………….... c b. Ochraceous to yellow or brown, sometimes with reddish or purplish tints, but never bright red or purple ……………………………………………………………………………. d c. Deep, clear, dark purple ………………………………………………………….…. C. lepida (41) c. Deep maroon or rose-purple. (Nodes somewhat thickened, not expanded nor pulvinate, but might be looked for here) ………………………………………………………………... C. elegans d. Sporangia reddish ochraceous to hazel or coppery; stalk long, slender, usually more than 6/7 total height …………………………………………………………………………… e d. Sporangia yellow, ochraceous or clay-colored to olivaceous or dusky; stalk shorter, thicker, never 6/7 total height ………………………………………………………………... g e. Hazel or coppery, usually over 0.3 mm in diameter; cup weIl-developed; stalk rarely exceeding 10 times diameter of sporangium ………………………………... C . languescens (39) e. Reddish ochraceous to hazel but not coppery; cup rudimentary or lacking; stalk 10-20 times diameter of sporangium …………………………………………………………………………..….. f f. Nodes hemispherical, dark, strongly concave on inner side; threads of net slender, not rigid nor flattened; dictydine granules dark ……………………….……. C. microcarpa (43) Index f. Nodes pulvinate, pallid, slightly concave on inner side; threads of net coarse, rigid, somewhat flattened; dictydine granules pale ……………………………. C. pachydictyon [currently considered Cribraria microcarpa (Schrad.) Pers.] g. Dark brown; stalk 1-2 times height of sporangium; net notably large-meshed; crowded, on leaves ………………………………………………………………………………………. C. laxa (40) g. Ochraceous to dusky; stalk usually longer; meshes of net not notably large; on wood ……. h h. Cup tending to be obconical; stalk expanded at apex …………………C. piriformis (46) h. Sporangia globose; stalk cylindrical or subulate, not expanded at apex …………..…. i i. Bright yellow to ochraceous or clay-colored ……………………………………………………... j i. Dingy olivaceous to dusky ……………………………………………………………………….... k j. Bright yellow to ochraceous; nodes pulvinate throughout; cup ample, well- defined …………………………………………………………………..….. C. aurantiaca (53) j. Dull ochraceous to clay-colored; nodes pulvinate only above; cup more or less replaced by flattened ribs, these merging gradually into net ……………………………… C. martinii k. Sporangia 0.5-0.7 mm in diameter; nodes pulvinate but expanded and angular; net with numerous free ends ……………………………………………………………….... C. intricata (38) k. Sporangia 0.3-0.5 mm in diameter; nodes compact, rounded; net with few free ends …………………………………………………………………………………….. C. tenella (51) l. Bright red; crimson or purple …………………………………………………..……….…. m l. Yellow, ochraceous, or olivaceous, to dull reddish brown ……………………………… q m. Deep, clear purple, rarely over 0.3 mm in diameter; nodes large, expanded, irregular ……………………………………………………………………………..… C. violacea (52) m. Lilac or reddish purple to crimson or brick-red; rarely under 0.3 mm. in diameter ………….n n. Deep maroon to reddish purple, mostly 0.3-0.5 mm in diameter; nodes small, prominent, somewhat thickened but not pulvinate, scarcely expanded ………………………………………………………………………..C. elegans (36) n. Reddish purple to crimson or brick-red; larger; nodes scarcely or not at all thickened, usually largo and irregular …………………………………………………………………... o o. Reddish purple, darkening with age, mostly 0.6-1 mm in diameter; nodes irregular, widely expanded; cup well-developed, obscurely ribbed, sometimes plicate ………… C. purpurea (47) Index o. Crimson to brick-red, sometimes darkening with age, rarely under 1 mm in diameter; cup never plicate; nodes scarcely expanded …………………………………………………………... p p. Dull crimson, 1-2 mm in diameter; net small-meshed, merging into the deep, smooth cup ………………………………………………………………………….. C. rubiginosa (48) p. Brick-red to reddish purple, tending to darken, 1-1.5 mm in diameter; net with large, open meshes, distinct from prominently ribbed cup ………………….… C. ferruginea (37) q. Clay-colored to olivaceous, densely crowded and then sessile or short-stipitate, or gregarious and then with longer stems; net weak, easily detached; cup deep in gregarious fruitings, not clearly defined when crowded …………………………………………………….. C. argillacea (33) q. Net well-developed, persistent; sporangia rarely if ever sessile …………………………..….. r r. Cup usually replaced by 8-15 firm ribs radiating from tip of stalk, these free or sometimes partially connected by delicate, fugacious membranes …… C. splendens (50) r. Cup present or absent, when present, often ribbed, but ribs connected by persistent membranes ……………………………………………………………………………..………s s. Sporangia minute, rarely over 0.2 mm in diameter, often smaller; cup often lacking …….…. t s. Sporangia larger, rarely under 0.2 mm in diameter, often much larger; cup always present ………………………………………………………………………………………………… u t. Bright yellow-brown to coppery; stalk 1-4 times height of sporangium; cup present or absent …………………………………………………………………….. C. minutissima (44) t. Hazel brown, not coppery; stalk 8-13 times height of sporangium; cup lacking ……………………………………………………………………..…. C. pachydictyon [currently considered Cribraria microcarpa (Schrad.) Pers.] u. Cup deep, strongly ribbed, perforated above, merging gradually into the coarsely meshed, irregular net; brown or bronze ………………………………………………..… C. macrocarpa (42) u. Cup not perforated, sharply distinguished from net ……………………………………………. v v. Dull orange-brown to ferruginous, sometimes darker with age ……………………….. w v. Hazel or bronze to purplish brown or blackish ………………………………………..… x w. Sporangia mostly 0.2-0.4 mm in diameter; spores orange-brown in mass; nodes sometimes thickened, but not pulvinate ………………………………………………………….. C. oregana (45) w. Sporangia mostly 0.6-0.7 mm in diameter; spores nut-brown in mass; net notably lax, with Hat, scarcely expanded nodes ……………………………………………………………. C. rufa (49) Index x. Dark purplish brown to nearly black, shining; cup bearing concentric lines of granules inside and out; spores verrucose, sometimes bearing a delicate, broken reticulation on surface ……………………………………………………………………...… C. atrofusca (34) x. Hazel to purplish brown, not shining; cup not bearing concentric lines of granules ……………………………………………………………………………………….. y y. Spores 7-8 m in diameter, angular in outline, bearing reticulate lines of warts ……………………………………………………………………………..… C. dictyospora (35) y. Spores rarely exceeding 6 m in diameter, reticulate lines faint or lacking …….…... C. vulgaris Genus Dictydium [currently considered a synonym of Cribraria] a. Surface net strongly ribbed below, merging above into a coarse reticulum; transverse filaments sparse; peridium tending to persist as an irregular membrane ……….. D. mirabile (55) [currently considered Cribraria mirabilis (Rostaf.) Massee] a. Ribs of surface net persisting nearly or quite to apex, connected by numerous delicate transverse filaments; reticulations, if present, restricted to tip …………………………………… b b. Reddish purple to deep purple or brown; sporangia usually nodding, often umbilicate above and below, with 30 or more ribs; stalk attenuated above, often tortuous ……………………………………………………………………. D. cancellatum (54) [currently considered Cribraria cancellata (Batsch) Nann.-Bremek.] b. Bright carrot-red; sporangia usually erect, with 14-16 longitudinal ribs; stalk cylindrical ………………………………………………………………………... D. rutilum (56) [currently considered Cribraria rutila (G. Lister) Nann.-Bremek.] Orden Echinosteliales Family Echinosteliaceae Genus Echinostelium a. Capillitium present; fructifications 0.3 mm or more tall ………………..…………………….…. b a. Capillitium lacking; fructifications under 0.2 mm tall ………………………..…………………. c b. Pale pinkish or yellowish to white; capillitium scanty, with few or no meshes, the ends mostly free; spores 6-9 m …………………………………………….….…. E. minutum (60) b. Ochraceous; capillitium a complete net, with few or no free ends; spores 9-10 m.……………………………………………………………………….… E. cribrarioides (57) Index c. Columella weII-developed, brown, fragile; spores pink or gray, mostly 13-14 m............................................................................................................................E. fragile (59) c. Columella lacking or very small and inconspicuous; spores smaller …………………………...d d. Sporangia golden yellow, fading to white; spores yellow or white, 6.5-8 m……………………………………………………………………………. E. elachiston (58) d. Sporangia rosy, not fading; spores pinkish, 9-10 m………………………… E. roseum [currently considered an invalid or doubtful name] Order Trichiales a. Capillitium of sold threads, attached to base and often to sporangial walls, never united into a net…………………………………………………………………………...………….Dianemaceae a. Capillitium of tubular threads, free or attached to base of sporangium, often united into a net……………………………………………………………………………………………Trichiaceae Family Dianemaceae [Dianemataceae] a. Sporangia black, minute, dehiscent by preformed lobes; capillitium with angular thickenings, appearing moniliform; spores dusky……………………………………….Listerella paradoxa (61) a. Sporangia not black; dehiscence irregular; capillitium not annular; spores bright-colored…...b b. Capillitial threads relatively stout, nearly straight, with many of the tips attached to the peridial walls…………………………………………………………………………...Dianema b. Capillitial threads slender, hair-like, coiled, with few attachments to the peridial walls.................................................................................................................................c c. Capillitium minutely sculptured; spores free…………………………….Calomyxa metallica (62) c. Capillitium smooth; spores clustered………………………………………...Minakatella longifila Genus Dianema a. Spores free…………………………………………………………………………………………...b a. Spores clustered…………………………………………………………………………………….d Index b. Sporangia flattened-pulvinate, thin, expanded on a broad base, merging into small plasmodiocarps; capillitial threads united above and below; spores finely reticulate ………………………………………………………………….… D. depressum (64) b. Sporangia pulvinate, sessile on a constricted base or rarely short-stipitate ……….... c c. Wall membranous, delicate, yellowish, iridescent, sometimes thickened with brown granular accretions; capillitium profusely branched and anastomosing; coarse at base, the slender extremities attached to wall………………………………………………………………….. D. nivale c. Wall membranous, rather firm, reddish ochraceous to dull red or brown, iridescent; capillitium sparsely branched with few anastomoses, not notably penicillate at tips when attached to wall………………………………………………………………………………………. D. harveyi (65) d. Plasmodiocarps robust; wall double, the outer layer opaque; capillitial threads 1.5-2.5 m in diameter, without marked expansions……………….………..…… D. corticatum (63) d. Plasmodiocarps slender; wall membranous; capillitial threads 2-3 m or more in diameter, with wide membranous expansions……………………………………. D. repens Family Trichiaceae a. Capillitium bearing spines, cogs or rings, sometimes nearly smooth or more or less reticulate, or With faint, poorly defined spirals intermixed with other markings; spirals sometimes well- marked in one species of Arcyria……………………………………………………………………...b a. Capillitium bearing 2-6 well-defined spiral bands, the spirals bearing spines, or smooth……..g b. Capillitium of free elaters, these usually short, simple or sparsely branched, if long, rarely forming a complete net………………………………………………………………….c b. Capillitium of long, profusely branched and anastomosing threads, typically united into a net……………………………………………………………………………………………...d c. Elaters warted, spiny or nearly smooth or minutely annulate; sporangiate to plasmodiocarpous or, if densely clustered, not heaped; wall rather thick, usually impregnated with granular material, appearing double, rarely with excreted lime…………………...Perichaena c. Elaters bearing faint and irregular spirals or nearly smooth; sporangia densely aggregated, usually heaped; wall thin, membranous, often iridescent……………………………….Oligonema d. Capillitium marked as in Oligonema, but threads united into an incomplete net……………………………………………………………………….Calonema aureum (77) d. Capillitium variously marked, but rarely with spirals and then with basal cup and fugacious peridium……………………………………………………………………………..e Index e. Peridium usually early-fugacious above the usually shallow, persistent, cup-like base, sometimes, in closely aggregated clusters, persisting at base, but calyculus then distinguishable; net elastic, often strongly so…………………………………………………Arcyria e. Peridium tending to be persistent, especially below, but not forming a morphologically distinct cup; capillitium somewhat elastic……………………………………………………………………...f f. Capillitium bearing warts or spines; sporangia small, sessile, heaped………...............................................................................Arcyodes incarnata (97) f. Capillitium bearing prominent coarse rings…………………………Cornuvia serpula (98) g. Peridium cartilaginous, thick, shining, opening by a preformed lid; elaters notably spiny………………………………………………………………………………………….Metatrichia g. Peridium membranous or thickened by accretion and then dull, opening irregularly or in lobate fashion or, if by a lid, then both cup and lid membranous; elaters spiny or smooth……….h h. Capillitium of thick-walled threads, the lumen often obscure or lacking, arising from the base and coiled about each other in spiral bundles, the penicillate tips attached to sporangial walls……………………………………………………Prototrichia metallica (66) h. Capillitium of thin-walled threads with evident lumen and with few or no attachments to sporangial walls………………………………………………………………………………i i. Threads of capillitium united into an intricate net, with few free ends………………..Hemitrichia i. Threads of capillitium broken into relatively short, unbranched or sparsely branched elaters, hence free ends numerous…………………………….……………………………………….Trichia Genus Perichaena a. Spores clustered in groups of 4-16, on leaves………………………………… P. syncarpon (72) a. Spores free; usually occurring on wood or bark……………………………………………..…. b b. Fructications predominantly plasmodiocarpous………….…………………………..…. c b. Fructifications predominantly sporangiate……………………………………………….. e c. Spores 10-14 m in diameter; plasmodiocarps dull yellow-brown to dark red-brown, long, slender, curved or net-like……………………………………………………..…. P. vermicularis (73) c. Spores 10 m or less in diameter; plasmodiocarps often shorter and usually accompanied by sessile, rarely stalked, sporangia…………………………………………..…………………….. d Index d. Dark reddish brown; plasmodiocarps often elongated or ring-like, varying to sporangiate, rarely stipitate; spores 7-10 m in diameter; capillitium rough to spiny………………………………………………………………….….. P. chrysosperma (67) d. Salmon-pink to ochraceous buff; spores 6-7 m in diameter; capillitium very slender, appearing closely annulate……………………………………………..…. P. microspora (70) e. Sporangia flattened on a broad, continuous base usually densely aggregated and angular from pressure; dehiscence circumscissile…………………………………………. P. depressa (69) e. Sporangia not notably flattened, often clustered but not usually angular; dehiscence circumscissile or irregular…………………………………………………………………………….. f f. Spores 15-17 m in diameter; sporangia stalked or sessile, purplish red……………………………………………………………………………..… P. pulcherrima f. Spores under 15 m in diameter; sporangia yellow to reddish brown or purplish black………………………………………………………………………………………….… g g. Sporangia mostly stalked; peridium bearing prominent warts; spores 9-11 m…. P. minor (71) [currently considered Hemitrichia minor G.Lister] g. Sporangia sessile; peridium not warted………………………………………………………….. h h. Spores 10-14 m, capillitium variable, up to 4 m in diameter……..… P. corticalis (68) h. Spores 9-10 m, capillitium slender, 1.5 m in diamete...………................ P. tessellata Genus Oligonema a. Dull olivaceous, spores warted ……………………………………………………. O. fulvum (75) a. Dull to shining yellow; spores reticulate …………………………………………………...…….. b b. Peridium granular, tough; sporangia elongate, erect, tending to be crowded in a single layer; spores with a nearly complete reticulation, the bands narrow .….. O. flavidum (74) b. Peridium scarcely granular, delicate; sporangia irregularly globose, tending to be heaped; spores with irregular reticulation, the bands often broad, pitted………………………………………………………………….…….. O. schweinitzii (76) Genus Arcyria a. Peridium fugacious except for base, which persists as a sharply defined calyculus ………. b Index a. Peridium tending to persist above base, which remains as a deep cup, with the true calyculus often poorly defined ……………………………………………………………………………..…… s b. Capillitium loosely attached to center of calyculus, readily breaking away as a whole in mature sporangia…………………………………………………………………………… c b. Capillitium firmly attached to calyculus, basal strands not readily separating …….…. i c. Dull green, fading to greenish ochraceous; calyculus notably small, narrow, funnel- shaped …………………………………………………………………………….… A. virescens (96) c. Yellow, rosaceous or gray, sometimes olivaceous with age; calyculus broader or wider…... d d. Yellow or buff……………………………………………………………………………...… e d. Red or reddish, sometimes smoky olivaceous…………………………………………… f e. Sporangia cylindrical, clear yellow, becoming bright ochraceous or buff; capillitium extremely elastic, the threads 3-4 m in diameter, bearing spines, cogs and reticulations..... A. nutans (90) [currently considered Arcyria obvelata (Oeder) Onsberg] e. Sporangia ovate, buff; capillitium scarcely elastic, the threads 1-1.5 m in diameter, annulate…………………………………………………………………………..….. A. annulifera (78) f. Spores 9-11 m in diameter; capillitium dense, slightly elastic, tending to fall away at maturity as a unit; reddish brown, fading to dull orange brown…….….. A ferruginea (83) f. Spores under 9 m; capillitium strongly elastic, not dense at maturity, readily breaking apart………………………………………………………………………………………….… g g. Fully expanded net tending to be erect; bright crimson, tardily fading to brownish red…………………………………………………………………………………….. A. incarnata (86) g. FuIIy expanded net drooping: colors usually dull and dingy, rarely bright……………..…….. h h. Dull crimson to reddish brown, rarely bright rose; capillitium bearing long spines; spores 7-9 m; fragments of peridium tending to remain attached to expanded net……………………………………………………………………………… A. oerstedtii (92) h. Dingy rosaceous to smoky olivaceous, capillitium bearing short spines, cogs and half- rings; spores 6-8 m; peridial fragments rarely persisting…….………….…. A. magna (89) i. Dull green to bluish gray, becoming dingy or dark with age…………………………………..… j i. Without greenish or bluish tints………………………………………………………………..…… k j. Cylindrical, clustered; cup funnel shaped………………………………….... A. glauca (84) Index j. Globose to short-cylindrical, scattered or gregarious; cup wide, bowl- shaped............................................................................................................... A. nigella k. White to yellow or ochraceous…………………………………………………………………...… l k. Salmon or pink to red or reddish brown………………………………………………………..… o I. Sporangia mainly cylindrical; capillitium marked by weak spirals, at least in part………………………………………………………………………….…. A. leiocarpa (88) [currently considered Hemitrichia leiocarpa (Cooke) Lister] I. Capillitium without spiral bands………………………………………………………...…. m m. Cup usually deep, bowl-shaped; sporangia globose to short cylindrical; sporangia white or pale gray…………………………………………………………………………..……. A. globosa (85) m. Cup shallow, saucer-shaped; sporangia white to ochraceous………………………………….n n. Sporangia mostly cylindrical, but varying to ovate, white to gray or ochraceous; capillitium spiny; cup smooth or stippled within…………………….………. A. cinerea (80) n. Sporangia globose to ovate or short-cylindrical, always bright ochraceous; capillitium marked with spines, cogs and bands; cup papillate to subreticulate within…………………………………………………………………..…….. A. pomiformis (93) o. Sporangia ovoid to short cylindrical, flesh colored; cogs on capillitium blunt or hammershaped in outline…………………………………………………………………………………. A. carnea (79) [currently considered an invalid or doubtful name] o. Sporangia cylindrical, usually brighter or darker in color; capillitium not bearing blunt cogs ………………………………………………………………………………………………….… p p. Spores 8-10 m in diameter………………………………………………………………. q p Spores mostly under 8 m in diameter…………………………………………….……… r q. Dull ruse, 3-4 mm tall, united by stalks into clusters of 2-20; stalks one-half total height……………………………………………………………………………….. A. corymbosa (81) q. Bright rose, 1 mm tall, not clustered; stalks very short……………………………..…. A. minuta r. Salmon to pink or bright rose; sporangia small, usually in small clusters………………………………………………………………………….. A. insignis (87) r. Bright red to brick red, fading to reddish brown; sporangia robust, often in extensive fruitings…………………………………………………………………….….. A. denudata (82) s. Sporangia large, bright yellow, olivaceous or brown, often touched with red; spores 9-11 m …………………………………………………………………………………….. A. versicolor (95) Index s. Sporangia of small or medium size; dull metallic, but not bright; spores 6-8 m ………….… t t. Sporangia rosy to brown or fading to ochraceous, gregarious or crowded but rarely superimposed; capillitium marked with warts and cogs, sometimes simulating spirals, but not bearing true spirals……………………………………………………. A. occidentalis (91) t. Sporangia copper-colored, turning dark brown or fading to ochraceous; sporangia often heaped and united into pseudoaethalia…………………………………………………..…. u u. Capillitium bearing at least some true spiral bands, these often faint and interspersed with spines and rings, attached at base but upper part often separating with persistent peridium………………………………………………………………………………….. A. stipata (94) u. Similar to A. stipata except that capillitium is marked by well developed spiral bands only ………………………………………………………………………...….. (Hemitrichia imperialis) [currently considered Arcyria imperialis (G.Lister) Q.Wang & Yu Li] Genus Trichia a. Typically sessile, sporangiate to plasmodiocarpous, sporangia rarely short-stalked……….. b a. Typically sporangiate and stalked, the stalks distinct, usually half or more of total height, rarely short-stalked or sessile………………………………………………………………………... h b. Elaters with two, rarely three, spirals, these tending to be open and loose…………………………………………………………………………..…… T. varia (111) b. Elaters with at least three, usually more spirals, these tending to be close and tight…………………………………………………………………………………………...….c c. Spores coarsely and prominently reticulate…………………………………. T. favoginea (104) c. Spores spinulose or minutely warted, or, if reticulate, reticulations delicate, visible only under high magnification………………………………………………………………………………..…… d d. Spores large, 13-18 m in diameter; sporangia dark purple to black….... T. alpina (99) d. Spores rarely exceeding 13 m in diameter………………………………………….…..e e. Fructifications umber brown to dark ochraceous; spores brown in mass…. T. macbridei (107) e. Fructifications yellow to reddish brown, sometimes darker with age; spores ochraceous in mass…………………………………………………………………………………………………….. f f. Dull yellowish or reddish brown becoming blackish when old; wall thickened with granular deposits………………………………………………………..…… T. contorta (101) Index f. Peridium olive or yellow, delicate, shining……………………………………………….. g g. Scattered or in small clusters; elaters smooth, 3-4.5 m; spores warted…... T. lutescens (106) g. Crowded or in extensive fruitings; elaters spiny, 5-6 m; spores delicately reticulate……………………………………………………………………….…….…. T. scabra (109) h. Spores coarsely and prominently reticulate; peridium papillose; elaters with short tips…………………………………………………………………………… T. verrucosa (112) h. Spores warted or spinulose or very delicately reticulate…………………………..……. i i. Elaters spinulose; sporangia brown, mottled; spore-mass yellow or orange………………………………………………………………………..………….. T. erecta (103) i. Elaters spineless or nearly so………………………………………………………………………. j j. Elaters of uniform thickness except at the short, often blunt, tips; sporangia subglobose or somewhat pyriform……………………………………………………….. T. subfusca (110) j. Elaters with long, slender, tapering tips; sporangia usually turbinate or pyriform……. k k. Sporangia top-shaped, dehiscent by a flat, membranous operculum; elaters 7-8 m in diameter, uniform at the center, but with long, tapering tips…………………. T. crateriformis (102) k. Sporangia dehiscent by lobes or irregularly above; elaters usually less than 6 m in diameter at center, tapering gradually from there to tips……………………………………………………… l l. Spore-mass ochraceous to brown; stalk brown, opaque……………….. T. botrytis (100) l. Spore-mass not ochraceous to brown; stalk translucent, at least above……………... m m. Spore-mass olivaceous yellow; stalk dark brown below, paler above, filled with spore-like cells; dehiscense irregular, leaving a cup-Iike base……………………………… T. decipiens (108) m. Spore-mass brick-red; stalk deep red, not filled with spore-like cells………. T. floriformis (105) [currently considered Metatrichia floriformis (Schwein.) Nann.-Bremek.] Genus Hemitrichia a. Spores coarsely and prominently reticulate……………………………………………………… b a. Spores nearly smooth to spiny or warted or, if reticulate, reticulations faint and visible only under high magnification……………………………………………………………………………… c Index b. Fructifications plasmodiocarpous, usually large and netted; capillitium spiny……………………………………………………………………….….. H. serpula (119) b. Sporangiate or forming small a plasmodiocarps; capillitium not spiny……………………………………………………………………... H. chrysospora (367) c. Spores and capillitium in mass dull orange to brick-red; peridium bearing conspicuous dark warts………………………………………………………………………………... H. paragoga (118) c. Spores and capillitium usually yellow, sometimes reddish brown but never brick-red; peridium not bearing conspicuous warts……………………………………………………….……………... d d. Primarily plasmodiocarpous, but often associated with pulvinate or globose sporangia……………………………………………………………………... H. karstenii (116) [[currently considered a variety of Trichia contorta (Ditmar) Rostaf.] d. Primarily sporangiate, rarely approaching plasmodiocarpous……………………….... e e. Sporangia cylindrical, often distorted, copper-colored to reddish brown, densely clustered, sometimes joined to form simple pseudoaethalia………………………………………………….. f e. Sporangia usually globose to pyriform, rarely cylindrical and then without coppery tints, usually free…………………………………………………………………………………………….. g f. Spirals of capillitium poorly and irregularly developed, often associated with spines and rings………………………………………………………………………….…. (Arcyria stipata) f. Spirals of capillitium strongly developed, without spines or rings, otherwise similar to A. stipata……………………………………………………………………….…. H . imperialis [currently considered Arcyria imperialis (G.Lister) Q.Wang & Yu Li] g. Sporangia sessile or with thick, short stalks……………………………………………………... h g. Sporangia usually with well-developed stalks, rarely short-stalked or sessile…………..…… j h. Sporangial wall typically hyaline, iridescent, sometimes encrusted; capillitium with 2- 4 smooth spirals……………………………………………………………… H. abietina (113) h. Sporangial wall usually opaque; capillitium with 4-6 spirals……………………………. i i. Sporangia large, wide in proportion to height; peridium pale yellow; capillitium with 5-6 spirals………………………………………………………………………………... H. montana (117) i. Sporangia of medium size; peridium dull yellow or olivaceous; capillitium usually with 4-5 spirals……………………………………………………………………………………… H. leiotricha Index j. Stalk hollow, filled with spore-like cysts; sporangia grayish or ochraceous, closely resembling Arcyria cinerea……………………………………………..……….. (A. leiocarpa) [currently considered Hemitrichia leiocarpa (Cooke) Lister] j. Stalk solid or hollow; sporangia bright yellow to yellow-brown……………………..….. k k. Capillitium distinctly spiny………………………………………………………….. H. intorta (115) k. Capillitium smooth or minutely roughened, not spiny…………………………………………… l l. Stalk expanding upward, merging gradually into the deep vase-like cup; capillitium minutely roughened……………………………………………………….…. H. clavata (114) l. Stalk cylindrical to base of peridium, distinct from the rather shallow cup; capillitium nearly smooth………………………………………………………………... H. stipitata (120) [[currently considered Hemitrichia calyculata (Speg.) M.L. Farr] Genus Metatrichia a. Sporangia sessile, dark purplish red, shining with metallic reflections; operculum sunken within a raised rim; spines on elaters 2-4 m ……………………………………….….. M. horrida a. Sporangia stalked, rarely sessile, deep maroon, nearly black to reddish brown or steel gray, shining with metallic reflections, operculum dome-shaped, without sunken rin, spines on elaters rarely over 2 m …………………………………………………………………... M. vesparium (121) [the current accepted name is Metatrichia vesparia (Batsch) Nann.-Bremek. ex G.W. Martin & Alexop.] Order Stemonitales [Stemonitidales] a. Fructification an aethalium………………………………………………………………………….b a. Fructification sporangiate, the sporangia scattered, clustered or sometimes massed into a pseudoaethalium……………………………………………………………………………………….c b. Capillitium a network of more or less horizontal, branching threads, the tips of the branches united by many chambered vesicles……………………Brefeldia maxima (124) b. Capillitium dendroid, the main stalks arising from the base, the tips of the branches free……………………………………………………………………………….Amaurochaete c. Wax present in stalk and columella, sometimes in capillitium and sporangial wall…Elaeomyxa c. Wax not secreted…………………………………………………………………………………….d Index d. Columella, stalk when present, and usually hypothallus conspicuously limy….Diachea d. Lime lacking, or rarely present as inconspicuous clusters of crystals imbedded in base or hypothallus…………………………………………………………………………………...e e Columella usually lacking; rarely present in some sessile forms…………………………………f e. Columella always present…………………………………………………………………………..g f. Fructification a pseudoaethalium; sporangia closely ] packed, the peridium fugacious except for conical base and cap; capillitium of sparsely branched threads coiled as a mass and united in basal cups and apical caps, the whole covered by a continuous membrane…………………………………………………………………………….Schenella [not a myxomycete, see Rammeloo, Icones Mycologicae 93-110, pl. 110. 1985 and Estrada et al., Mycologia 97(1):142-152. 2005] f. Fructification sporangiate, sporangia free or clustered, sometimes united into pseudoaethalium, but capillitium then not in coiled spirals united in basal and apical cups……………………………………………………………………………………………...g g. Sporangia sessile on a broad or constricted base which is rarely contracted into a short, thick stalk……………………………………………………………………………………………………...h g. Sporangia mostly stalked, rarely sessile and then with a distinct columella from which the capillitium arises…………………………………………………………………………………………j h. Outer wall of peridium gelatinous when wet…………………………………..Colloderma h. Outer wall of peridium not gelatinous when wet……………………………………………i i. Peridium membranous above, thickened with granular deposits below and usually including scale-like masses of lime crystals in lower part and hypothallus……Leptoderma iridescens (363) i. Peridium membranous, hyaline, iridescent throughout; lime crystals lacking……..Diacheopsis j. Columella enlarged at apex into a cupulate disk from which the capillitium depends…………………………………………………………………………..Enerthenema j. Columella sometimes attaining apex, usually shorter, and not bearing a cupulate apical disk; capillitium usually arising from entire columella or from base of sporangium…….....k k. Peridium evanescent, but typically replaced by a surface net developed under the periphery, remaining after the peridium has been shed, and united with the capillitium…………..Stemonitis k. Peridium persistent or, if evanescent, without surface net; capillitium often scanty, sometimes abundant but then without surface net and usually with many terminal branchlets……………….l Index l. Peridium ochraceous, delicate, persistent, but breaking up into small, scale-like fragments which remain attached to tips of capillitial branchlets.........................................................................Clastoderma debaryanum (184) I. Peridium not breaking up into small fragments which remain attached to tips of capillitium……………………………………………………………………………………….m m. Peridium dark, tough, persistent, early splitting above into petaloid lobes which remain attached at base as a cup………………………………………………Barbeyella minutissima (185) m. Peridium not splitting into petaloid lobes arising from a basal cup……………………………n n. Stalk typically translucent, hollow, often yellow at the base…………………Macbrideola n. Stalk dark, opaque, not hollow……………………………………………………………...o o. Peridium though, metallic, shining, tending to be long-persistent as a whole…Lamproderma o. Peridium usually early evanescent or, if persistent, membranous, delicate………..Comatricha Genus Amaurochaete a. Capillitium and spores fuscous to bone brown in mass; spores pale, 7.5-10 m ……………………………………………………………………………………A. ferruginea (126) [currently considered Symphytocarpus flaccidus (Lister) Ing & Nann.-Bremek.] a. Capillitium and spores black in mass; spores dark, usually 11 m or more…………………….b b. Capillitium soft, woolly, circinate……………………………………………………………c b. Capillitium rigid, irregular……………………………………………………………………d c. Capillitium entirely of slender threads, attached at top and bottom; spores prominently warted…………....................................................................................................A. comata (125) c. Capillitium arising from stout basal stalks, branching and anastomosing toward slender upper threads; spores minutely roughened………………………………………………...A. tubulina (129) d. Spores warted or spinulose……………………………………………………A. atra (127) d. Spores strongly reticulate………………………………………………A. trechispora (128) Index Genus Elaeomyxa a. Wax secreted only in stalk, and collar when present, spores dark, over 10 m ..…………………………………………………………………………………….E. cerifera (130) a. Wax secreted in stalk, capillitium and sporangial wall, spores pale, 7-10 m ……………………………………………………………………………E. miyazakiensis (131) Genus Colloderma a. Sporangia dark, shining, spores pale gray under lens, mostly 11-12 m ….. C. oculatum (122) a. Sporangia brown, duller, spores dark gray under lens, mostly 14-16 m …. C. robustum (123) Genus Diachea a. Hypothallus, stalk and columella yellow or orange…............................................................. b a. Hypothallus, stalk and columella white…………………………………………………………... c b. Spores pale, minutely warted, 11-13 m .…………………………….. D. thomasii (137) b. Spores dark, strongly and irregularly warted, 13-14 m………………. D. megalospora c. Sporangia typically cylindrical to ovate, rarely subglobose, spores pale under lens, minutely roughened, 8-11 m …………………………………………………………….… D leucopodia (133) c. Sporangia globose or nearly so………………………………………………………………….... d d. Stalks usually half or more of total height; spores conspicuously marked…………… e d. Stalks usually short or lacking, rarely over half of total height; spores inconspicuously marked………………………………………………………………………..………………… f e. Spores sparsely but prominently spiny or warted………............................... D. bulbillosa (132) e. Spores bearing prominent wart-like protuberances, these often forming a coarse and imperfect reticulation……………………………………………………………… D. splendens (135) f. Spores minutely spiny or warted, 7-11 m in diameter…………………... D. radiata (134) f. Spores faintly reticulate, 10-13 m in diameter……….……………… D. subsessilis (136) Index Genus Schenella [not a genus of myxomycetes, see Rammeloo, Icones Mycologicae 93-110, pl. 110. 1985 and Estrada et al., Mycologia 97(1):142-152. 2005] a. Capillitium smooth, spores black in mass, distinctly verrucose, 5-6 m ….… S. simplex (139) a. Capillitium rough, spores fuscous in mass, minutely roughened, 3-4 m ...S. microspora (138) Genus Diacheopsis a. Spores sparsely papillose, 6-7 m in diameter …………………………………..… D. pieninica a. Spores 12 m or more in diameter, spinulose …………………………………………………. b b. Spores long spinulose, 12 -14 m in diameter …………………………..….. D. metallica b. Spores minutely spinulose, (14-) 18-19 m in diameter …………………..… D insessa Genus Enerthenema a. Spores clustered in groups of 4-12 ………………………………………... E. berkleyanum (140) a. Spores free …………………………………………………………………………………………. b b. Spores minutely warted, 10-12 m, apical disk not exceeding 0.2 mm in diameter ……………………………………………………………….…… E. papillatum (142) b. Spores coarsely warted, 11-14 m, apical disk 0.3-0.5 mm in diameter ……………………………………………………………. E. melanospermum (141) Genus Stemonitis a. Spores reticulate, the reticulations prominent or faint, rarely lacking ………………………… b a. Spores spiny to warted or smooth, not reticulate……………………………………………….. h b. Spores prominently but often incompletely banded-reticulate……………………….… c b. Spores spiny-reticulate, verrucose-reticulate, or, if banded-reticulate, the bands faint……………………………………………………………………………………………... d Index c. Sporangia 2-5 mm tall, nearly black, short-stalked or sessile, in dense, sometimes agglutinated clusters; spores 11-13 m ……..…………………………………. S. trechispora (154) [currently considered Symphytocarpus trechispora (Berk. ex Torrend) Nann.-Bremek.] c. Sporangia under 3 mm tall, brown, distinctly stalked, in small but not agglutinated clusters; spores 7-8 m …………………………………………………………………………. S. inconspicua d. Sporangia deep fuscous to black, usually fruiting in dense clusters……………..…... e d. Sporangia vinaceous or lilac, usually fruiting in loose clusters………………………… f e. Clusters small, black; sporangia 2-5 mm tall; stalk usually less than one-fourth total height; spores distinctly spiny-reticulate, 8-9 m …………………………………..… S. nigrescens (150) [currently considered Stemonitis fusca Roth] e. Clusters large, conspicuous, fuscous to deep reddish brown; sporangia mostly 6-20 mm tall; stalk usually over one-fourth total height; spores prominently to delicately warted-reticulate, 7.5- 9 m …………………………………………………………………………. S. fusca var. fusca (146) [currently considered Stemonitis fusca Roth] f. Sporangia lilaceous brown; surface net tending to be fugacious above; spores rather conspicuously verrucose-reticulate, mostly 7-8 m ……………….….. S. virginiensis (156) f. Sporangia somewhat darker, spores usually under 6 m ………………………..……. g g. Sporangia purplish ferruginous, 2.5-5 mm tall; surface net often fugacious above; spores faintly and irregularly banded-reticulate, 5-6 m …………………………….... S. hyperopta (148) [currently considered Stemonitopsis hyperopta (Meyl.) Nann.-Bremek.] g. Sporangia dark IiIaceous brown, 1.7-3.2 mm tall; surface net persistent above; spores delicately reticulate, 3.2-4.5 m ……………………………………………………. S. microsperma [currently considered Stemonitopsis microspora (Lister) Nann.-Bremek.] h. Spores united in clusters; sporangia always dark……………….………………………. i h. Spores free, sporangia dark or pale………………………………………………………. j i. Sporangia free at bases and apices, connate between, with discoid platelets at junctions between adjacent sporangia; spores pale, 12-13 m ………... S. confluens var. syncarpon (144) [currently considered Symphytocarpus syncarpus (Yamash.) Y.Yamam.] i. Sporangia densely clustered, more or less united, sometimes into a pseudoaethalium but without discoid platelets at junctions of sporangia; spores dark, 8-10 m ……… S. uvifera (155) j. Deep fuscous to black………………………………………………………………………. k j. Brown to vinaceous or pallid……………………………………………………………….. n Index k. Sporangia free at bases and apices, elsewhere united by capillitial branches bearing discoid platelets at junctions; spores pale, spinulose, 11-12 m …….. S. confluens var. confluens (144) [currently considered Symphytocarpus confluens (Cooke & Ellis) Ing & Nann.-Bremek.] k. Sporangia gregarious or massed, but not united by branches bearing platelets…………..… l l. Capillitium dense, with many branches; meshes of surface net delicate, mostly 30 m or less; spores papillate to nearly smooth, 7.5-9 m………………. S. fusca var. papillosa [currently considered Stemonitis fusca Roth] l. Capillitium open, with few branches; meshes of surface net coarse, many 30-100 m ……………………………………………………………………………………………... m m. Sporangia short, obtuse, short-stalked, up to 3.2 mm in total height; meshes of surface net brown, conspicuously broad and flattened; spores prominently spiny-warted, 10.5-12.5 m ……..……………………………………………………………………… S. mussooriensis (149) m. Sporangia, when well-developed, notably long, acuminate, 10-20 mm or more in total height; meshes of surface net reddish brown, often with metallic reflections; spores minutely warted, 7-9 m …………………………………………………………………………….... S. splendens (153) n. Spores nearly smooth, rarely reaching 7 m ………………………………………….... o n. Spores distinctly warted, usually over 7 m ……………………………………..……… p o. Sporangia bright ferruginous, often in large fruitings, usually 7-15 mm tall; spores 5-7 m ………………………………………………………………………………………. S. axifera (143) o. Sporangia pale ferruginous, in small tufts, 2-6 mm tall; spores 4-5 m .…...… S. smithii (152) [currently considered Stemonitis axifera (Bull.) T.Macbr.] p. Bright brown; stalk rarely attaining one-third total height, often much shorter; surface net persistent above; often fruiting on living plants………………………. S. herbatica (147) p. Dull brown or pallid; stalk usually one-third or more of total height; surface net tending to be fugacious above; rarely fruiting on living plants………………………………..……. q q. Wood-brown; columella giving rise to many coarse branches with expanded nodes and tending to expand into a cup-like enlargement at tip…………………………... S. flavogenita (145) q. Drab or pale; columella may attain the apex, but often dispersed well below tip; capillitium delicate………………………………………………………………………………..… S. pallida (151) Genus Comatricha a. Peridium membranous, iridescent, persistent, especially below………………………………. b Index a. Peridium typically evanescent, not rarely persistent in C. typhoides, rarely if ever in other species…………………………………………………………………………………………………. e b. Sporangia 0.2-0.3 mm in diameter, densely aggregated, sometimes forming a pseudoaethalium; peridium dark, iridescent brown; stalks slender, sometimes attaining half total height; capillitium scanty, irregular………………………..…. C. aggregata (159) b. Sporangia 0.3-0.5 mm in diameter, tufted but not united; peridium bluish, silvery or bronze; stalk lacking or very short and stout; capillitium profuse……………………….... c c. Spores spiny, 10-13 m; peridium silvery or bronze, with bluish tints…….. C. caespitosa (160) [currently considered Paradiachea caespitosa (Sturgis) Hertel ex H.Neubert, Nowotny & K.Baumann] c. Spores reticulate; peridium rarely with bluish tints…………………………………………….... d d. Spores incompletely verrucose-reticulate, 12-14 m; peridium silvery or bronze……………………………………………………………………….. C. cylindrica (162) [currently considered Paradiachea cylindrica (Bilgram) Hertel ex H.Neubert, Nowotny & K.Baumann] d. Spores banded-reticulate, 10-11 m; peridium violaceous brown…… C. rispaudii (175) [currently considered Paradiachea rispaudii (Hagelst.) Hertel ex H.Neubert, Nowotny & K.Baumann] e. Capillitium lax, open, with few or no anastomoses, forming at most a very open net with many prominent free ends……………………………………………………………………………………. f e. Capillitium intricate, with many anastomosing branches, forming a net, usually dense, with short or rarely no free ends…………………………………………………………………………... k f. Sporangia long-cylindrical, fruiting in large, dark, densely aggregated clusters……... g f. Sporangia short-cylindrical to ovate or globose, scattered or clustered but not densely aggregated…………………………………………………………………………………..… h g. Sporangia deep fuscous to black, very long and drooping, 10-50 mm; capillitium with very few anastomoses; spores conspicuously verrucose-reticulate…………………….. C. longa (167) [currently considered Stemonaria longa (Peck) Nann.-Bremek., R.Sharma & Y. Yamam.] g. Sporangia dark brown to black, usually semi-erect, 2-8 mm in length; capillitium open, the few anastomoses forming a very open net toward the columella, with long, branching but rarely anastomosing ends; spores verrucose…………………………………………... C. irregularis (165) [currently considered Stemonaria irregularis (Rex) Nann.-Bremek., R.Sharma & Y.Yamam.] h. Sporangia mostly short-cylindrical, sometimes varying to ovate or subglobose; columella attaining tip or nearly so, with numerous lateral branches…………………….. i Index h. Sporangia globose or depressed, columella rarely exceeding center of sporangial cavity, dividing at tip or sometimes at or below base into two or more main branches………………………………………………………………………………………… j i. Capillitium open, rigid, branching toward ends and terminating in spinose tips which project beyond surface of spore-mass; spores prominently and coarsely reticulate, 10-13 m ……………………………………………………………………………….…… C. mirabilis (171) i. Capillitium open, lax, delicate, the tips slender or somewhat enlarged but not projecting from spore-mass; spores spinulose, 6.5-7 m ………………………………………... C. longipila (168) j. Tips of capillitial branches notably enlarged; spores closely and minutely spinulose, mostly 11-13 m ……………………………………………………….……. C. fimbriata (164) [currently considered Paradiacheopsis fimbriata (G.Lister & Cran) Hertel ex Nann.- Bremek.] j. Tips of capillitial branches not enlarged; spores prominently spiny, 12-13(-20) m ……………………………………………………………………..….. C. acanthodes (157) [currently considered Paradiacheopsis acanthodes (Alexop.) Nann.-Bremek.] k. Sporangia predominantly elongate, cylindrical, subcylindrical or fusiform to elongate- ovate…………………………………………………………………………………………………….. l k. Sporangia predominantly globose or subglobose, varying to broadly ovate…………………. t l. Spores olivaceous brown to purplish brown or black in mass………………………..... m l. Spores pale lilaceous brown to ferruginous or pinkish in mass………………………… r m. Robust, black; spores dark, coarsely warted, mostly 10-13 m …………… C. suksdorfii (178) m. Slender, dark brown to purplish brown; spores usually smaller and less prominently marked……………………………………………………………………………………………….… o n. Spores delicately reticulate…………………………………………… C. dictyospora (174) [currently considered and invalid or doubtful name] n. Spores not reticulate……………………………………………………………………...... o o. Spores minutely warted, with 2-4 prominent clusters of larger warts to the hemisphere; stalks usually long, black, with a silvery sheath; peridium tending to be persistent…. C. typhoides (181) [currently considered Stemonitopsis typhina (F.H.Wigg.) Nann.-Bremek.] o. Spores uniformly warted; stalks without silvery sheath; peridium not persistent…………..... p p. Sporangia deep brown or blackish, cylindric to ovate-cylindric or ovate; stalks long, usually much more than half total height…………..….. Cylindrical forms of C. nigra (172) Index p. Sporangia dark brown or deep purplish brown, always cylindric; stalks usually less than half total height…………………………………………………………………………... q q. Sporangia slender, acuminate; stalks one-third to half total height………… C. aequalis (158) [currently considered Stemonitopsis aequalis (Peck) Y.Yamam.] q. Sporangia plump, obtuse, stalks one-fifth to one-fourth total height.. ..C. subcaespitosa (177) [currenty considered Stemonitopsis subcaespitosa (Peck) Nann.-Bremek.] r. Sporangia fusiform, pinkish brown; stalks usually much more than half total height; capillitium uniform, with no conspicuously large branches………..….. C. tenerrima (180) r. Sporangia cylindrical to cylindrical-ovate; stalk not exceeding half total height; capillitium with conspicuous large branches or forming a net with few free ends…….... s s. Sporangia pale brown, cylindrical, acuminate; capillitium dense, with large basal branches, many anastomoses and few free ends………………………………………….. C . pulchella (173) s. Sporangia reddish brown, ovate-cylindrical; capillitium rather open, with few anastomoses and many free ends………………………………………………… Elongate forms of C. laxa (166) t. Sporangia dark brown to deep fuscous or blackish………………………….………….. u t. Sporangia bright-colored.…………………………………………………………………... x u. Sporangia deep fuscous or blackish; stalks long, often four-fifths or more of total height, without hyaline sheath; capillitium delicate, intricate, with many free ends; spores 9-10 m ……………………………………………………………………….. Usual forms of C. nigra (172) u. Sporangia dark reddish brown, not fuscous; stalks rarely attaining two-thirds of total height………………………………………………………………………………………………...…. v v. Sporangia broadly ovate; columella reaching almost to tip, giving rise to uniform branches throughout its length…………………………..…….. Ovate forms of C. laxa (166) v. Sporangia globose or nearly so; columella tending to divide into large branches below tip……………………………………………………………………………………………….. w w. Total height 0.6-1.5 mm; capillitium dark, rigid, with a nearly complete surface net; spores 11-13 m ………………………………………………………………………………..…. C. rigidireta w. Total height 0.3-0.6 mm; capillitium more open, without conspicuous surface net, bearing nodular enlargements, spores 9.5-10.5 m ……………………………………..……. C. nodulifera x. Columella reaching about two-thirds of sporangial cavity, giving off many large branches throughout; peridium persisting at base of sporangium as a cup or collar with capillitium attached………………………………………………………….. C. rubens (176) [currently considered Collaria rubens (Lister) Nann.-Bremek.] Index x. Columella not exceeding center of sporangium, often shorter, and dividing into a few stout main branches, or sometimes stem dividing below base of sporangium…………. y y. Columella usually present, dividing from near base to middle of sporangium, rarely higher, into a few stout branches from which bulk of capillitium arises……………………. C. lurida (169) [currently considered Collaria lurida (Lister) Nann.-Bremek.] y. Columella very short or lacking, dividing at or near base, or stem dividing below base of sporangium into several stout branches…………………………………………... C. elegans (163) Genus Macbrideola a. Peridium persistent………………………………………………………….….. M. scintillans (183) a. Peridium fugacious at an early stage…………………………………………………………….. b b. Capillitium forming an open net with few or no free ends; spores united in clusters………………………………………………………………….…. M. synsporos (179) b. Capillitium consisting of simple or branched strands with few or no anastomoses, sometimes lacking; spores free.……………………………………………………………... c c. Capillitium of robust strands which remain stout to periphery; base of peridium tending to persist as a collar…………………………………………………………………………..... M. cornea c. Capillitium of more or less flexuous strands which become attenuated toward the periphery…………………………………………………………………………………………….…. d d. Spores minutely and uniformly warted, 8.5-9.5 m; capillitium sometimes reduced to one or two short branches of the columella, or lacking………… M. decapillata (161, 182) d. Spores minutely warted with scattered clusters of larger warts, 6.5-7 m; capillitium of 3 or 4 branching threads……………………………………………………. M. martinii (170) Genus Lamproderma a. Spores strongly and completely banded-reticulate, 11-16 m; short-stalked or sessile, rarely plasmodiocarpous………………………………………………………………. L. cribrarioides (190) [currently considered Meriderma cribrarioides (Fr.) Mar.Mey. & Poulain] a. Spores not banded-reticulate; crested, warted or spiny to nearly smooth, the warts sometimes arranged in a usually imperfect reticulate pattern……………………………….…… b b. Spores bearing vesicular crests, these often forming a broken Index reticulation…………………………………………………………………… L. cristatum (191) b. Spores not bearing vesicular crests………………………………………………………. c c. Peridium silvery blue, marked with conspicuous depressed, dark areas; spores dark, echinulate, 12-15 m ……………………………………………………………… L. gulielmae (193) c. Peridium uniform, without depressed dark areas……………………………………….………. d d. Stalks long, relatively slender, usually greatly exceeding half the total height……..…e d. Sessile or with relatively stout, short stalks rarely exceeding half the total height…... g e. Columella divided below center of sporangial cavity into several stout branches which give rise to the circinate capillitium; spores minutely punctate, 7-9 m ………… L. arcyrionema (187) [currently considered Collaria arcyrionema (Rostaf.) Nann.-Bremek. ex Lado] e. Columella not divided; capillitium rigid, the numerous branches arising mainly from the tip of the columella…………………………………………………………………………………………… f f. Sporangia globose, 0.5-1 mm in diameter, varying to elongate-ellipsoid or cylindrical, total height 2-4 mm or sometimes more; branches of capillitium dark at base; spores dark, 11-14 m ………………………………………………………..…. L. columbinum (189) f. Sporangia globose, mostly 0.3-0.4 mm in diameter, sometimes smaller; main branches of capillitium pale at base, becoming abruptly darker; spores pale, 7-9 m……………………………………………………………………..……. L. scintillans (198) g. Capillitium attached to peridium, especially below, by yellow funnel-shaped expansions of tips, these often bearing peridial fragments after dehiscence, dark throughout except for expansions; spores dark, bearing conspicuous warts or blunt spines often arranged in a subreticulate pattern, mostly 12-15 m …………………………………….... L. atrosporum (196) [currently considered Meriderma cribrarioides (Fr.) Mar.Mey. & Poulain] g. Capillitium without funnel-shaped expansions at tips, usually free from peridium, occasionally attached by slender tips…………………………………………………………………………….… h h. Sporangia fusiform on short stalks, more than twice as tall as wide; peridium firm, black, shining, persistent; columella reaching apex, sometimes emerging; spores minutely warted, 12-14 m ………………………………………………….…… L. fusiforme [currently considered Comatricha fusiformis (Kowalski) Kowalski] h. Sporangia usually subglobose or ovate, rarely cylindrical but then not fusiform; peridium membranous; columella not emerging…………………………………………… i i. Spores bearing both spines and tubercles…………………………………... L. tuberculosporum i. Spores not bearing both spines and tubercles……………………………………………………. j Index j. Spores strongly spinose, 15-20 m, sporangia globose to ovate- cylindrical…………………………………………………………….…... L. echinulatum (192) j. Spores warted or spinulose, rarely attaining 15 m, usually much smaller; sporangia globose to ovate, rarely cylindrical…………………………………………………………... k k. Columella pale brown capillitium pallid, with rosy tints; sessile or short-stalked; spores warted, mostly 11-12 m ……………………………………………………………….… L. pulchellum (195) k. Columella dark; capillitium dark except for tips which may be pale or colorless; usually stalked, the stalk often half the total height…………………………………………………………….……... I l. Spores minutely verrucose, with small blunt spines or nearly smooth, mostly 11-14 m, sometimes larger………………………………………………………………. L. sauteri (197) l. Spores rarely exceeding 13 m ………………………………………………….……….. m m. Sporangia small, mostly 0.2-0.4 mm in diameter; capillitium dark; spores strongly warted or spiny…………………………………………………………………………………………………..... n m. Sporangia usually larger (0.3-)0.5-1.4 mm in a diameter; spores minutely warted or spinulose…………………………………………………………………………………………….… o n. Stalk black; spores bearing large, sharp, irregularly scattered spines, mostly 11-13 m ………………………………………………………………………….. L. muscorum (194) n. Stalk pale dull orange, spores bearing blunt spines or warts, sometimes arranged in a reticulate pattern ………………………………………………………. L. verrucosum (199) o. Capillitium somewhat rigid at base, tending to become lax and flexuous, the main threads pale as they leave the columella, becoming darker, then fading toward the colorless tips; sporangia of moderate size, 0.3-1 mm in diameter; spores pale, minutely warted, 8-11 m ………………………………………………………………………………….. L. arcyrioides (186) o. Capillitium rigid and dark at base, becoming somewhat circinate and fading to the pale tips; sporangia robust 0.7-1.4 mm in diameter; spores dark, verrucose, 10-12 m .. L. carestiae (188) [currently considered Meriderma carestiae (Ces. & De Not.) Mar.Mey. & Poulain] Order Physarales a. Capillitium calcareous, usually intricate, entire fructification often limy, the lime in the form of non-crystalline granules…………………………………………………………………Physaraceae a. Capillitium non-calcareous or rarely bearing aggregations of crystalline lime, peridium and often stipe limy, the lime frequently crystalline…………………………………………Didymiaceae Index Family Physaraceae a. Capillitium duplex, i.e., composed of two distinct systems………………………………………b a. Capillitium essentially homogenous……………………………………………………………….d b. Primarily plasmodiocarpous, but sometimes fruiting as pulvinate sporangia or massed into a pseudoaethalium; capillitium of limy plates, massed transversely, connected with a nearly limeless network of slender tubes bearing numerous, often hooked spines……………………………………………………………Cienkowskia reticulata (200) [currently considered Willkommlangea reticulata (Alb. & Schwein.) Kuntze] b. Primarily sporangiate, if plasmodiocarpous, then usually accompanied by sporangia; capillitium not spinose………………………………………………………………………….c c. Sporangia ovate; peridium Smooth, shining; capillitium a limy network, connected with and interpenetrating a limeless network of flattened tubules…………………..Leocarpus fragilis (201) c. Sporangia deeply introverted, thimble-like, rarely plasmodiocarpous; peridium rough; capillitium composed of stout calcareous spines arising from the inner wall and a network of slender threads bearing a few calcareous nodes………………………..Physarella oblonga (202) d. Capillitium a network of calcareous tubes of nearly uniform diameter; limeless connecting tubules few or none…………………………………………………….Badhamia d. Capillitium a network of hyaline limeless tubules with calcareous nodes at many or all of the junctions………………………………………………………………………………….e e. Fructification an aethalium; pseudocapillitium present, often more conspicuous than capillitium………………………………………………………………………………………….Fuligo e. Fructification sporangiate or plasmodiocarpous, rarely approaching aethalioid; pseudocapillitium lacking……………………………………………………………………………….f f. Plasmodiocarpous, cylindrical, pendent, often anastomosing to form a 3-dimensional net………………………………………………………………………Erionema aureum (224) [currently considered Fuligo aurea (Penz.) Y.Yamam.] f. Sporangiate or plasmodiocarpous, rarely pendent; plasmodiocarps, when anastomosing, forming a 2-dimcnsional net…………………………………………………g g. Sporangiate; dehiscence circumscissile, often by a preformed lid, the lower portion persisting as a deep cup………………………………………………………………………………...Craterium g. Sporangiate or plasmodiocarpous, rarely somewhat aethalioid; dehiscence irregular or lobate; lower portion of peridium remaining as at most a shallow, irregular cup………..Physarum Index Genus Badhamia a. Spores formed in clusters, these sometimes breaking apart at maturity; capillitium strongly badhamioid, lacking hyaline connecting threads…………………………………………….…….. b a. Spores free; capillitium varying from typical badhamioid to somewhat physaroid, with a few short, hyaline connecting threads………………………………………………………………….… g b. Spore clusters very loose, readily falling apart; spores globose, uniformly warted or nearly so…………………………………………………………………….. B. utricularis (216) b. Spore clusters tending to persist; spores elliptical or ovate, with warts or spines on exposed outer surfaces, these scanty or lacking elsewhere…………………….……….. c c. Spore clusters composed of 10-40 spores, the larger clusters hollow; sporangia flesh-colored to dingy white……………………………………………………………………..… B. versicolor (217) c. Spore clusters usually smaller, not hollow……………………………………………………….. d d. Sporangia yellow, orange or greenish, fading to dingy………………….... B. nitens (210) d. Sporangia white, gray or iridescent, rarely with rosaceous tints………………………. e e. Sporangia borne on firm, dark, usually short stalks………………………. B. papaveracea (214) e. Sporangia sessile or on pale, weak, membranous stalks………………………………………. f f. Walls thin, translucent, sometimes almost limeless; exposed area of spores uniformly warted……………………………………………………………………… B. capsulifera (204) f. Walls calcareous, white or sometimes with purplish or rosaceous tints; exposed area of spores irregularly warted, the warts tending to be in lines; sporangia large, densely clustered or heaped, often resembling an aethalium……………………... B. populina (215) g. Capillitium represented by tubular calcareous columns, simple or forked, extending from base to peridium……………………………………………………………………….. B. ainoae (366) [currently considered Badhamiopsis ainoae (Yamash.) T.E.Brooks & H.W.Keller] g. Capillitium netted, varying from typically badhamioid to somewhat physaroid………………. h h. Sporangia with bright green or yellow tints………………………………………….…… i h. Sporangia without bright green or yellow tints……………………………………….….. j i. Sporangia stalked, yellowish green or gray with a yellow base; capillitium badhamioid…………………………………………………………………….…. B. viridescens (218) i. Sporangia pulvinate or plasmodiocarpous, rarely stalked; green, often quickly fading; capillitium physaroid…………………………………………………….…. see Physarum decipiens Index j. Spores elliptical with a low longitudinal ridge; sporangia pulvinate or plasmodiocarpous, dingy or somewhat ochraceous…………………………………………….. B. ovispora (212) j. Spores globose or subglobose, without longitudinal ridge……………………………… k k. Columella or pseudocolumella cylindrical, rarely lacking; base of peridium tending to persist as a cup; stipitate or sessile on a constricted base; sporangia dark gray to purple- brown………………………………………………………………………………….. B. obovata (211) [currently considered Craterium obovatum Peck] k. Columella lacking or represented by a thickened base; rarely cupulate; sporangia paler to white…………………………………………………………………………………………………….. l l. Lime scanty, peridium delicate, more or less iridescent; capillitium always badhamioid……………………………………………………………………………….…… m l. Lime usually abundant, coating peridium thickly; capillitium often appearing physaroid………………………………………………………………………………..…….. n m. Sporangia usually stalked, the stalks hyaline, often long, slender, weak; peridium smooth…………………………………………………………………………..….. B. utricularis (216) m. Sporangia usually sessile, rarely stalked, the stalks short, yellowish………... B. foliicola (206) n. Spores dark, somewhat oval, encircled by a pale band; sporangia sessile………………………………………………………………………. B. dearnessii (205) [currently considered Badhamia goniospora Meyl.] n. Spores globose, not encircled by a pale band, or very inconspicuously so………….. o o. Spores warted, with very open overlying reticulation; usually stalked, the stalk often more than half the total height…………………………………………………………….… B. gracilis (207) [currently considered Badhamia melanospora Speg.] o. Spores rarely with overlying reticulation; usually sessile or, if stalked, stalks short, rarely attaining half total height……………………………………………………………………….…….. p p. Sporangia subglobose, small, sessile on a broad base, usually under 0.5 mm in diameter, densely crowded, drab to lilaceous, pinkish or white; peridium porcelain-like, smooth or somewhat rugose…………………………………………………. B. lilacina (208) p. Sporangia usually larger, without drab or lilaceous tints; peridium not porcelain- like…………………………………………………………………………………………….… q q. Sporangia densely heaped, pure white or ashy-white, stalked or sessile; stalks, when present, weak, strand-like…………………………………………………………………….... B. cinerascens q. Sporangia gregarious or sometimes crowded, but not heaped, often colored below……………………………………………………………………………………………………. r Index r. Spores lilaceous or violaceous by transmitted light, nearly smooth…………..……….. s r. Spores dark by transmitted light, distinctly warted or spinulose………………………… t s. Sessile or stalked; hypothallus prominent, red; stalk, when present, red; base of sporangium often reddish………………………………………………………………………….. B. panicea (213) s. Always stalked; hypothallus inconspicuous, dark; stalk black or dark brown; base of sporangium brown…………………………………………………………….………….. B. iowensis t. Spores densely and irregularly verrucose; stalk, when present, yellowish or brown except at darkened base; sporangia never orbiculate……………….. B. macrocarpa (209) t. Spores densely spinulose; stalk, when present, black; sporangia often orbiculate………………………………………………………………………… B. affinis (203) Genus Fuligo a. Spores small, 6-9 m in diameter, aethalia often very large …………………… F. septica (223) a. Spores large, over 10 m in diameter; aethalia usually of small or medium size…………... b b. Aethalia usually slender, often plasmodiocarpous in aspect, or thin and broadly effused ..……………………………………………………………………………………….. c b. Aethalia compact, pulvinate……………………………………………………….……… d c. Spores often elliptical; crust white……………………………………………….. F. cinerea (219) c. Spores spherical; crust greenish gray or yellowish green………….………. F. muscorum (222) d. Cortex thin, fragile, not strongly calcareous, early fugacious; spores nearly smooth, 11-13 m in diameter; sometimes appearing as densely massed sporangia……………………………………………………………….….. F. intermedia (220) d. Cortex thick, spongy, calcareous; spores dark, rough-tuberculate to subreticulate, 15- 20 m in diameter………………………………………………………… F. megaspora (221) Genus Craterium a. Dehiscence circumscissile or by fragmentation of upper part of sporangium, which is often different in texture from lower portion, but rarely forming a distinct lid, and wall then mealy or rough…………………………………………………………………………………………………… b Index a. Dehiscence by a clearly defined, preformed lid, often sunken………………………….…….. d b. Sporangia pinkish to deep purple; cup deep, persistent………. C. paraguayense (229) b. Sporangia without pinkish or clear purple colors……………………………………….. c c. Sporangia pale or whitish above, ochraceous to brownish below, rarely entirely brown; capillitium white or ochraceous; cup deep, persistent………………….. C. leucocephalum (227) c. Sporangia bright yellow or greenish yellow, fading to ochraceous or dingy white; capillitium orange or yellow, fading; cup tending to be shallow, finally breaking into petaloid lobes………………………………………………………………………………….. C. aureum (225) d. Sporangia gray with a reddish base; walls limy; nodes pinkish; spores sparsely but prominently spiny to subreticulate………………………………..…………. C. rubronodum d. Sporangia brown; walls smooth, glossy, sometimes bearing lime granules, spores minutely spiny………………………………………………………………………………….. e e. Sporangia ochraceous brown to dark brown or reddish brown; nodes large, white………………………………………………………………………………….. C. minutum (228) e. Sporangia pinkish brown; nodes small, brown……………………………….C. concinnum (226) Genus Physarum a. Primarily sessile; sporangiate to plasmodiocarpous or pseudoaethalioid, sometimes with a constricted base or attached to a weak, stalk-like extension of the hypothallus, rarely with true stalks………………………………………………………………………………………………….... b a. Primarily stalked and sporangiate; sessile or plasmodiocarpous fruitings often occur, but are usually accompanied by stalked sporangia………………………………………………..……….. c b. Peridium single, or, if double, the inner layer firmly attached to the outer limy crust; lime sometimes in scales or patches, then readily flaking away……………….……. Key I b. Peridium double, rarely triple, the inner layer distant from the outer layer or layers, or, if appressed, readily separating; lime usually deposited as a persistent crust……………………………………………………………………………………..… Key II c. Columella present……………………………………………………………….……………. Key III c. Columella lacking; pseudocolumella sometimes present ……………………………….…….. d Index d. Nodes massed in center to form a calcareous central body or pseudocolumella………………………………………………………………………… Key IV d. Calcareous central body or pseudocolumella usually lacking, rarely present….…… e e. Sporangia strongly compressed laterally, annulate, saucer-shaped or lobed…………. Key V e. Sporangia globose to oval or lenticular…………………………………………………………… f f. Capillitium reticulate, not notably dichotomously branched and radiating from base of peridium; nodes angular or rounded, rarely fusiform………………………………… Key VI f. Capillitium dichotomously branched, usually with many cross-connections, radiating from base of peridium; nodes mostly fusiform………………………………………. Key VII KEY I a. Predominantly sporangiate, but often forming, small, rarely branched or netted, plasmodiocarps……………………………………………………………………………………..… b a. Predominantly plasmodiocarpous, often forming a net; often broken into small plasmodiocarps or sporangia………………………………………………………………..………. p b. Capillitium strongly elastic, expanding when wall is broken……..………. P. famintzinii b. Capillitium not notably elastic…………………………………………………………..…. c c. Spores tending to be elliptical in outline, encircled by a pale band……..… P. ovisporum (278) c. Spores globose or nearly so, not encircled by a pale band……………………………….…… d d. White or ashy gray, without ochraceous tints. Some species keyed under following may at times be white………………………………………………………………..……….. e d. Usually distinctly colored or dark, sometimes ochraceous or dingy yellowish white………………………………………………………………………………………..….. g e. Sporangiate on a constricted base; peridium thin, nearly translucent, except for a white, limy reticulum on surface………………………………………………………….………… P. gilkeyanum e. Sporangiate on a broad base; peridium not bearing a limy net…………………………..……. f f. Capillitium scanty, nearly limeless; peridium thin, delicate, with at most a scanty deposit of lime; plasmodiocarps rare, simple; plasmodium yellow…………… see P. nudum (275) f. Capillitium abundant, limy; peridium fragile but bearing abundant lime flakes; plasmodium white, or sometimes yellow before fruiting; spores pale….. P. cinereum (243) Index f. Capillitium abundant, limy; peridium thick, calcareous; plasmodiocarps often well- developed; plasmodia white; spores dark…………………………………... P. vernum (299) g. Sporangia in dense, heaped clusters…………………………………………………………….. h g. Sporangia scattered or crowded, but not heaped…………………………………………….…. i h. Green or yellow, sometimes ochraceous or pallid; sometimes on weak stalks……………………………………………………….………………… P. virescens (300) h. Dull, dark violaceous brown, varying to pallid or white; never stalked………………………………………………………………………. P. confertum (246) i. Sporangia crowded, cylindric or irregular, often bluntly lobed, clay-colored to snuff brown…………………………………………………………………………….…… P. digitatum (253) i. Sporangia scattered or gregarious, rarely crowded, not clay-colored nor snuff brown……………. j. j. Peridium nearly limeless, membranous, gray, iridescent; sessile on a constricted constricted base or sometimes with weak stalks……………………….….. P. nudum (275) j. Peridium usually notably limy…………………………………………………………..….. k k. Predominantly yellow…………………………………………………………………………..…… l k. Predominantly red, brown or green…………………………………………………………..….. m l. Bright chrome yellow; when lime is continuous, wall may appear double…………………………………………………………………………. P. luteolum (265) l. Yellow-brown, often with white, yellow or reddish scales or patches; lime rarely continuous………………………………………………………..…………. P. decipiens (249) m. Nodes rounded, yellow, with red centers; sporangia red, scarlet or orange, sometimes fading……………………………………………………………………………….... P. lateritium (261) m. Nodes angular, rarely with red centers………………………………………………………….. n n. Sporangia small, mostly 0.3-0.5 mm in diameter; peridium reddish brown or brown, with pale spots; nodes small, deep ochraceous or brown……….….. P. braunianum (240) n. Sporangia larger, mostly 0.5-1.2 mm in diameter; nodes large, angular…….……….. o o. Scarlet, red-brown or olive-brown; peridium thin, rugulose; nodes sometimes reddish internally…………………………………………………………………….……. P. rubiginosum (288) o. Reddish to orange or green, often fading to ochraceous or dingy white; peridium smooth but often with embedded scales……………………………………………………. P. auriscalpium (234) Index p. Capillitium elastic, duplex, of large white spikes borne on peridium and small yellowish fusiform nodes on a dichotomous net; fructification of rosette-like plasmodiocarps often fusing into a pseudoaethalium, varying to separate, sessile or stalked sporangia……………………………………………………………….…….. P. gyrosum (259) p. Capillitium neither duplex nor elastic………………………………………………..……. q q. Dull yellow to ochraceous…………………………………………………..……... P. serpula (290) q. White or grayish white……………………………………………………………………………… r r. Spores pale violaceous, 6-8 m ………………………………………………….. P. sessile r. Spores darker, larger…………………………………………………………………..……. s s. Spores medium brown, warted, (9-)10-12 m; peridium limy, rugose; p