Summary:
Features include 1) a hazel brown to darker brown, silky-fibrillose cap, 2) adnexed gills that are whitish then grayish brown, 3) a fibrillose-satiny stem with a turnip-like bulb, the stem pallid at the top, more brown below, 4) a strong, fruity or rancid or unpleasant odor, 5) dull brown spore deposit, and 6) nodulose spores. Its presence in the Pacific Northwest is indicated by Ammirati(1).

Cap:
1.5-3cm across, conic then convex with umbo; "hazel or snuff brown; silky-fibrillose, shining", (Phillips), 3-5cm across, acutely umbonate; umber to chestnut; minutely fibrillose, (Hansen), conic, then expanded to sharply umbonate; umber or hazel-brown; fibrous-cracked, (Moser), 3.8-7.6cm across, bell-shaped then flat or slightly rounded, with pronounced umbo; dark brown, sometimes with a silvery superficial coating that tends to hide the color; smooth, soapy-feeling but not viscid when wet, drying silky, (Ammirati), 2-3.5(4.5)cm across, conic to bell-shaped when young, later bell-shaped to flat, always with a pronounced, +/- acute umbo, margin incurved for a long time, acute; hazel brown, usually darker in center; smooth becoming radially fibrillose to split, margin hung with remnants of cortina when young, (Breitenbach)

Flesh:
pallid, whitish, (Phillips), thin, firm; white, (Ammirati), thin; whitish, (Breitenbach)

Gills:
"adnexed; whitish when young, then pale brown", (Phillips), whitish when young, (Hansen, Moser), white at first, then dull grayish brown, (Ammirati), ascending and narrowly attached, 60-80 reaching stem, broad, 1-3(5) subgills between neighboring gills; gray-white becoming light gray-brown; edges white-floccose, (Breitenbach)

Stem:
4-6cm x 0.4-0.8cm, base with a distinct bulb; pallid at top, more brown below; fibrillose, (Phillips), 5-7cm x 0.4-0.7cm, with a prominent, slightly flattened bulb 0.8-1cm; flushed with cap color, whitish at top, (Hansen), 5-7cm x 0.4-0.8cm, bulb 0.6-1cm; colored or whitish, at top whitish, (Moser), with turnip-like bulb at base, stem rigid, usually longer than width of cap; pallid at top, brown below; satiny, (Ammirati), 4-6(7)cm x 0.3-0.6cm, cylindric, base with a white, napiform [turnip-shaped], +/- marginate bulb up to 1cm wide, stem fragile, solid becoming hollow; light brown, top paler to whitish; upper half finely fibrillose, (Breitenbach)

Veil:
cortina present when cap opens (Moser)

Odor:
"strong, fruity or rancid", (Phillips), unpleasant of chestnut catkins (Ammirati), musty to faintly radish-like (Breitenbach), mild, radish-like, (Buczacki)

Taste:
mild, herbaceous to radish-like, (Breitenbach)

Microscopic spores:
spores 7-9 x 5-6.5 microns, nodulose with rather large nodules, pleurocystidia 40-55 x 13-19 microns, thinnish-walled, colorless, some incrusted, (Phillips), spores 9-10 x 6-7 microns, with 5-6 nodules in outline; cystidia 50-60 x 12-18 microns, mostly crested, (Hansen), spores 8-10 x 5.5-7.5 microns, particularly nodulose, (Moser); spores (6.5)7-9 x 5.5-6.5 microns, mostly 8 x 6.5 microns, angular-nodulose, irregularly polyhedral, with 6-10 prominent rather coarse nodules; basidia 4-spored, 22-27.5 x 6.5-9 microns, clavate or subventricose; pleurocystidia 38-55 x 13-19 microns, mostly 45-50 x 18 microns, ventricose above a rather slender pedicel, with obtusely rounded apex, the wall thin to moderately and uniformly thickened (1.0-1.6 microns), colorless, cheilocystidia of two kinds, one like pleurocystidia but shorter and with less of a pedicel, the other of short thin-walled clavate cells like the basidia in size and shape; gill trama of parallel, compactly arranged hyphae, with fusoid-ventricose cells 5.5-13 microns in diameter; cap surface a compact layer 40-60 microns deep, of hyphae parallel to the surface and radially arranged, 4-10 microns in diameter, with brown walls bearing incrustations of brown pigment, the surface layer not sharply separated from underlying trama; apex of stem with rare, widely scattered dermatocaulocystidia resembling the pleurocystidia, occasional clusters of elongated, thin-walled dermatocaulocystidia that are sometimes septate, and some tangled superficial hyphae with abundant clavate to cylindric terminal cells, base with sparse tangled superficial hyphae, no dermatocaulocystidia; laticiferous hyphae present in stem tissue, but not seen in gill or cap trama; most septa with clamp connections, (Grund), spores 7.5-10.7 x 5.9-7.9 microns, nearly round to elongate, with 8-11 tubercles [nodules], yellow-brown; basidia 4-spored, 30-33 x 7-10 microns, clavate, with basal clamp connection; pleurocystidia similar to cheilocystidia, cheilocystidia 50-80 x 14-21 microns, fusiform to clavate, thick-walled (1-2.5 microns thick), only some with apical crystals, abundant clavate cells present among them; cap cuticle of periclinal hyphae 5-13 microns wide, light yellow-brown and encrusted, septa with clamp connections; hyphal ends showing on surface on stem apex, (Breitenbach)

Spore deposit:
snuff brown (Phillips), dull brown (Ammirati), gray-brown (Breitenbach), gray-brown (Buczacki)

Notes:
There are collections from BC at Pacific Forestry Centre and University of British Columbia. The University of Washington has collections from WA, OR, AK, and MI. Grund described a collection from NS. It also occurs in Europe.

EDIBILITY

very poisonous, contains muscarine, (Ammirati)