Summary:
Myxomphalia maura is characterized by a grayish brown cap that often becomes centrally depressed, broad whitish gills, a grayish brown stem, and growth on burnt soil. Smith(15) mentions some confusion in the species concept in Europe: the Friesian species Agaricus maurus has a dry cap and long-decurrent gills, but the concept accepted in Europe is that of Ricken (1915) which is the same as the one he describes in Smith(15) as Omphalina maura (cap viscid when moist but soon dry and glistening, gills broadly adnate or with a slight decurrent tooth). Smith also says that the latter cannot be regarded as the same as one he found in Michigan (also with broadly adnate gills) that corresponds to one illustrated by Lange from Denmark. M. maura is common in the western United States, (Smith).

Cap:
1-3.5(5)cm across, convex or centrally depressed with incurved margin, becoming flat or centrally depressed; dark grayish brown or olive-brown to blackish brown, fading to gray or paler as it dries; "viscid when moist but soon dry and often shiny, smooth", (Arora), 1-3.5(5)cm across, convex to convex-depressed with incurved margin, expanding to broadly convex or nearly flat when old, the disc often shallowly depressed; 'very dark grayish brown (near "olive-brown" or "mummy brown") and evenly colored or margin only slightly paler, slowly fading to pale gray or at times nearly white'; bald, "viscid when moist but soon dry and glistening", cap skin separable, margin finely striate at first, (Smith), "grey brown, convex, cuticle glutinous when damp, margin stays incurved, streaked, up to 3cm across", (Schalkwijk-Barendsen), hygrophanous, dark brown to blackish brown; viscid, bald, (Bigelow(6))

Flesh:
thin; white to grayish, (Arora), thin but pliant; dark watery gray, (Smith)

Gills:
"adnate to slightly decurrent, close"; "white to pale grayish (usually paler than cap)", (Arora), bluntly adnate to slightly decurrent, close, 3 tiers of subgills, gills broad; white or grayish but always much paler than cap or stem; edges even, (Smith), "decurrent and arched because the cap stays curved down, relatively broad", close, relatively broad; whitish to pale gray, (Schalkwijk-Barendsen)

Stem:
2-6cm x 0.2-0.5(0.6)cm, more or less equal; "colored more or less like cap or slightly paler, but not fading as quickly"; smooth, (Arora), 3-6cm x (0.1)0.2-0.4cm, equal, stuffed with floccose white pith, cartilaginous; colored as cap or slightly paler; top pruinose but soon becoming bald and polished overall, (Smith), brittle (Lincoff)

Odor:
not distinctive (Smith), slightly rancid-spermatic (Breitenbach for Europe), mild, or (at least in Europe) farinaceous or fruity, (Bigelow(4))

Taste:
somewhat farinaceous to mild, (Smith, Bigelow(6)), mild to slightly bitterish (Breitenbach for Europe)

Microscopic spores:
spores 4.5-6.5 x 3.5-4.5 microns, broadly elliptic to nearly round, "smooth or very minutely ornamented, amyloid", (Arora), spores 4.5-5 x 3.5-4 microns, broadly elliptic to nearly round, amyloid, "smooth or with very minute amyloid scattered warts (use oil immersion)"; basidia 4-spored, 18-20 x 4.5-5 microns; pleurocystidia and cheilocystidia similar, (40)50-90 x 6-9 microns, "subcylindric above an abruptly narrowed pedicel", colorless, "thin-walled or often the walls somewhat thickened"; clamp connections present, (Smith), spores 4.5-6.5 x 3.5-4.5 microns, nearly round to broadly elliptic, "smooth or verruculose, amyloid, walls slightly thickened"; basidia 4-spored, 14-20 x 4.5-6 microns; pleurocystidia and cheilocystidia usually abundant, 30-60(90) microns long, protruding 20-35 microns beyond hymenium, 6.5-10 microns wide, cylindric or subfusoid or fusoid-ventricose, tenpin-shaped at times, colorless or faintly brownish, walls smooth, thin or slightly thickened; clamp connections present, (Bigelow(6), 1975), spores smooth, not verruculose, even with scanning electron microscope, (Bigelow(4), 1979, using North American specimens)

Spore deposit:
white (Arora, Smith, Bigelow(6))

Notes:
Myxomphalia maura material was examined from WA, OR, ID, and QC, (Bigelow(6)). There are collections from BC at the Pacific Forestry Centre and the University of British Columbia. It has been reported from AB by Schalkwijk-Barendsen(1), and from NS and ME by Bigelow(4). It also occurs in Europe and has been reported from Asia and North Africa, (Breitenbach(3)).

EDIBILITY

unknown (Arora, Smith)

Synonyms and Alternate Names:
Fayodia maura (Fr.) Singer
Mycena maura Kuehner
Omphalina maura (Fr.) Quel.