Summary:
Features include 1) a hygrophanous appendiculate cap that develops fibrous-silky sooty-brown to blackish zones and spots on a sooty-brownish, later pale ground, 2) close to crowded gills that are pale then brown to brown-violet, 3) a white stem that is pale above a fragile transient avellaneous ring and sooty-brown fibrillose below the ring, 4) growth in clumps on alder, and 5) microscopic characters including small spores that are bean-shaped in part and lack a conspicuous germ pore, rostrate cystidia and pleurocystidia shaped like typical chrysocystidia but lacking the distinctive content. It is rather rare during most seasons (Smith(5)).

Cap:
2-6cm across, obtuse when young, expanding to obtusely bell-shaped and finally flat or with a slight umbo; at first viscid from a blackish brown to pale grayish brown coating of universal veil fibrils, the pallid grayish brown fibrils of the cap cuticle soon showing through, at maturity with a broad blackish brown patch or patches or streaks "and with pale avellaneous to dark wood brown appressed fibrils over the remainder"; margin "typically appendiculate with pallid to wood brown cottony triangular patches of veil remnants"^, (Smith), 2-5cm across, "fibrous-silky, sooty-brown to blackish zones and spots on sooty-brownish, later pale ground", (Moser), up to 5cm across, convex to expanded conic-convex; hygrophanous, with pale fibrils soon brown to blackish, "bunching together to form broad appressed scales on a whitish to dingy brownish background", margin "appendiculate with white then brownish fibrils", (Courtecuisse)

Flesh:
soft, fairly thick; whitish and unchanging, stem "pallid within but pinkish in base when cut"^, (Smith), brownish gray (Courtecuisse)

Gills:
depressed-adnate, crowded, narrow; pallid when young, "cinnamon-drab" when old, edges white; edges floccose, (Smith), brown-violet, (Moser), notched, quite close; pale brownish to dingy chocolate brown, edge frosted whitish, (Courtecuisse)

Stem:
6-12cm x 0.6-1.4cm, "slightly narrowed downward, fleshy and fibrous (not fragile), solid becoming hollow"; pallid near top; surface densely fibrillose and lower part entirely covered or merely streaked with blackish brown fibrils, some with an apical ring and surface above it fibrillose scurfy, (Smith), fibrous; "pale above ring, below sooty-brown, soon spotted", (Moser), up to 5cm long and 0.5cm wide, cylindric; whitish, with brown then blackish fibrils especially in lower part, (Courtecuisse)

Veil:
some with an apical avellaneous ring on stem, cap margin typically appendiculate, (Smith), fragile fairly transient ring on stem, cap margin appendiculate, (Courtecuisse)

Odor:
fungoid (Smith), none (Courtecuisse)

Taste:
mild (Smith)

Microscopic spores:
spores 5-6 x 3-3.5 microns, elliptic to oblong in face view, bean-shaped in profile, smooth, apical germ pore inconspicuous, moderately dark chocolate-color in KOH, reddish tawny in Melzer''s reagent, wall thin; basidia 4-spored, 14-18(20) x 4.5-7 microns, narrowly clavate, colorless in KOH; pleurocystidia abundant, 32-46 x 9-15 microns, "obovate-mucronate or the apical fingerlike projection considerably drawn out (up to 6-15 microns long)", walls thin, smooth and colorless, "content homogeneous in KOH or rarely with a few refractive particles", homogeneous in Melzer''s reagent, cheilocystidia "similar to pleurocystidia or merely saccate and up to 18-20 microns wide"; clamp connections mentioned with cap trama, (Smith), spores 4.5-5.5 x 2.7-3.5 microns, without pore; cystidia with bill, (Moser)

Notes:
The distribution is at least WA and OR (Smith). Paul Kroeger has a collection from BC. According to Breitenbach(4) it also occurs in Europe.

EDIBILITY

Synonyms and Alternate Names:
Drosophila maculata (C.S. Parker) Kuehner & Romagn.