Key to families of Myxomycota

1	Trophic phase simple amoebae or plasmodia having no shuttle movement of the protoplasm	(Protosteliomycetes, Protosteliales) 2
	Trophic phase a free-living, multinucleate, coenocytic, saprobic plasmodium having schuttle movement of the protoplasm	(Myxomycetes) 4
2(1)	Flagellate cells absent	Protosteliaceae
	Flagellate cells present	3
3(2)	Spores borne singly at the tips of hair-like stalks, on columnar, dendroid or morchelloid sporophores	Ceratiomyxaceae
	Spores (1-4) borne borne in sporangiate sporophores with short stalks not on hair-like stalks or morchelloid sporophores	Cavosteliaceae
4(1)	Sporophore development subhypothallic, the plasmodium protoplast rising internally through the developing stalk in stipitate forms	5
	Sporophore development epihypothallic, stalk, when present, secreted internally, hollow, or partially filled with strands	(Stemonitales) Stemonitidaceae
5 (4)	Spores in mass black, violet-brown, dark purple-brown, ferruginous, deep red or purple; by transmitted light usually purple-brown or deeply tinted, rarely pallid	(Physarales) 6
	Spores in mass pallid, white or bright coloured, sometimes brown, rarely black; by transmitted light pallid to bright coloured, yellow-brown, smoky-brown or dingy, but never purple-brown	7
6 (5)	Peridial lime granular; capillitium calcareous, rarely limeless, usually consisting either of calcareous tubules or of limeless, slender tubules connecting calcareous nodes	Physaraceae
	Peridium lime granular or crystalline; capillitium consisting of typically limeless thread-like, dark to pallid tubules, these occasionally exhibiting inclusions of crystalline lime, sometimes scanty, rarely lacking	Didymiaceae
7 (5)	Peridium persistent in whole or in part; true capillitium lacking; pseudocapillitium when present of tubular, irregular filaments or of perforated plates which may fray out into threads	(Liceales) 8
	True capillitium typically present; if lacking then peridium early fugacious and sporocarps minute	10
8 (7)	Sporophores sporangiate or plasmodiocarpous, generally small, often minute; pseudocapillitium and dictydine granules lacking	Liceaceae
	Sporophores sporangiate, pseudoaethalioid or aethalioid; pseudocapillitium or dictydine granules may be present	9
9 (8)	Dictydine granules lacking	Lycogalaceae
	Dictydine granules present; peridium usually netted, interstices usually fugacious	Cribrariaceae
10 (7)	Stalked, minute, rarely exceeding 0·5 mm in total height; peridium sometimes persistent in part or in whole; stalk filled with granular material; columella typically present, rarely lacking; capillitium, when present, scanty or forming an open globose net or branching and anastomosing; spores in mass white, yellowish, pinkish, gray or brown	11
	Sessile or stalked, larger; columella absent; capillitium usually abundant, of individual threads or a network, the threads sometimes delicate and solid, but mostly course, hollow and conspicuously sculptured; spores in mass white, ochraceous, yellow, orange , or red	(Trichiales) 12
11 (10)	Spores in mass white, cream-coloured, yellow, pink, gray, or rarely pink-brown; peridium delicate, evanescent at an early stage	13
	Spores in mass brown; peridium persistent, either as a whole or in fragment which cling to the tips of the capillitium	(Echinosteliales) Clastodermataceae
12(10)	Capillitium threads typically slender, rarely exceeding 2 µm diam., appearing solid, smooth or ornamented	Dianemataceae
	Capillitium threads typically coarser, rarely below 2 µm diam., tubular, generally conspicuously ornamented	14
13(11)	Flagellate trophic phase present; nuclei with a single, central nucleolus	(Echinosteliales) Echinosteliaceae
	Flagellate trophic phase absent; nuclei with many peripheral nucleoli	(Echinosteliopsidales)Echinosteliopsidaceae
14(12)	Capillitium threads with thickenings in the form of spirals	Trichiaceae
	Capillitium threads smooth or thickened with cogs, rings, half rings, spines or warts, never with spirales	Arcyriaceae