Summary:
Features include 1) a dark brown to sometimes ochraceous brown cap that is densely fibrillose to fibrillose-scaly, 2) adnate, whitish gills that become grayish brown or yellow-brown with white edges, 3) a brownish fibrillose stem that is equal or with the base a little swollen, often darker brown at base, 4) non-distinctive odor, 5) snuff brown spore deposit, 6) smooth spores, and 7) other microscopic characters. |Var. helobia was described separately by Kuyper(1) as a new variety, but this variety has been raised to species level as Inocybe helobia. Kuyper(1) differentiates it as showed in the SIMILAR section. |Var. rhacodes has the gill edge "at least partly consisting of protruding, catenate, brown-incrusted elements, with terminal element resembling cheilocystidia", whereas var. lacera and var. helobia (the latter here regarded as Inocybe helobia) lack such protruding catenate elements on the gill edge, (Kuyper(1)). |Grund & Stuntz described a variety heterosperma from NS with spores extremely variable in size and shape, (Grund(6)). Var. heterosperma was also found by Cripps(1) in ID, and Phillips(1) says found in WA also, but Kuyper(1) regards this variety as a synonym of var. lacera. |The Kuyper(1), Phillips(1) and Cripps(1) descriptions here are for the type variety.

Cap:
1-4cm across, convex at first then flat with an umbo; dark brown; densely fibrillose to fibrillose-scaly, (Phillips), 1.5-4cm across, typically hemispheric, convex, or less frequently nearly flat, not umbonate or indistinctly so; medium or dark brown when young or protected from the elements, light brown or pale yellow brown when old or when weathered; at first woolly-tomentose over entire cap, becoming areolate [cracked like dried mud] in center, outwardly lacerate with recurved [upcurved] scales, "tips of scales typically lighter than cap color, particularly at margin", "margin turned under or not, entire, often obscured by fibrillose scales, occasionally split when weathered", center rarely with tan veil material, causing cap to appear smoother and lighter colored, (Cripps), 1.2-4.2cm across, bell-shaped - convex, conic-convex, convex, flat-convex to finally flat, "with margin inflexed when young and then subappendiculate to straight", "often prominently umbonate but sometimes only indistinctly umbonate"; dark brown around center, towards margin brown to ochraceous brown, sometimes ochraceous brown all over; coarsely fibrillose to subsquamulose [somewhat finely scaly], at margin not rimulose [not finely cracked], subtomentose-smooth around center, but cap covering "later breaking up and then recurvately (sub)squamose, exceptionally very conspicuously so", veil covering absent or (very) indistinct, (Kuyper)

Flesh:
pallid brown (Phillips), white, watery tan, in stem firm, (Cripps), whitish in cap, reddish brown to dark brown in stem, but near top of stem sometimes with a lilac tinge, (Kuyper)

Gills:
adnate; grayish brown; edges whitish, (Phillips), broadly or narrowly attached, depressed at top of stem, crowded when young, moderately broad, 0.2-0.8cm broad; "white at first, then yellow brown, cocoa brown, rather light colored, may bruise darker brown", (Cripps), adnate, moderately crowded, 35-50 reaching stem, 1-3 subgills between neighboring gills, gills 0.2-0.8cm broad, (sub)ventricose; "whitish when young, exceptionally yellowish, finally ochraceous, ochraceous brown to olivaceous brown", edges whitish or colored as faces; edges almost even to subfimbriate [somewhat fringed], (Kuyper)

Stem:
1-3cm x 0.2-0.5cm, equal or with base a little swollen; brown like cap; fibrillose, (Phillips), 1-4.5cm x 0.3-0.6(1)cm, "long or very short, often buried in sand, stout in young specimens", longer and thinner when old, equal or narrowing toward base, straight or flexuous [wavy]; "dingy white, light brown, yellow brown, dark brown, darker toward base", white at top; rough fibrous, or rarely smoother, smooth above cortina, (Cripps), 2.5-11cm x 0.1-0.6cm, equal to somewhat widened at base, but without bulb, solid becoming fistulose; "whitish to buff in upper half, sometimes with reddish sheen or lilac tinges, brown or reddish brown half-way, dark brown to almost blackish brown at base", progressively darkening when old; "not pruinose, longitudinally white-fibrillose, often rather coarsely so", (Kuyper)

Veil:
cortina fibrous, tan, ephemeral [fleeting], copious on cap margin of young specimens, rarely tan veil material seen on center of cap (Cripps), cortina present when young; veil layer on cap absent or indistinct, (Kuyper)

Odor:
none (Phillips), typically fungoid, or absent, (Cripps), faint, indistinct to subspermatic, (Kuyper), none, fungoid, or faintly of green corn, (Miller), faint, bleach, (Buczacki)

Taste:
not distinctive (Bessette), not distinct, (Kuyper), mild but do not taste because of toxins (Miller)

Microscopic spores:
spores 14-16.7 x 5-6 microns, long bean-shaped, smooth, (Phillips for var. lacera), spores 10-16 x 4.5-6 microns (Lincoff), spores 10-15(18) x 4.5-6(7.5) microns (Moser), spores 10-18 x 4-6 microns, elliptic to subcylindric, smooth; pleurocystidia and cheilocystidia "thin-walled, subcylindric to subventricose or ventricose-subovoid", rounded or obtuse at apex, (Bessette); spores 12-14 x 4.5-5 microns, cylindric, long elliptic, smooth, slightly angular, with thick walls; basidia (2-)4-spored, 23-27 x 8-9 microns, clavate; pleurocystidia common, 54-68 x 10-19 microns, "subfusiform, with fine crystals or none at apex", walls thickened, 1-2(3) microns, colorless, cheilocystidia similar to pleurocystidia or broader, some subcapitate, paracystidia 25-30 x 10-15 microns, thin-walled, typically clavate, but variable; cap cuticle a trichoderm, of hyphae 10-12 microns wide, "encrusted, pigmented, no swollen or slightly swollen"; clamp connections present in all tissues, (Cripps for var. lacera), spores (9.0)10.0-15.5(16.0) x 4.0-6.0(6.5)spores, "smooth to minimally angular, often with a conspicuous suprahilar depression", reminding of Boletus-spores; basidia 4-spored, a few 2-spored, 25-32 x 9-11 microns; pleurocystidia frequent, (45)46-74(78) x (13)14-21(22) microns, (sub)fusiform to cylindric-subfusiform, "sometimes tending to subutriform, at apex sometimes rounded but more often acute, sometimes mucronate, slightly thick-walled", wall up to (1.5)2.0 microns thick and colorless (but yellow in one collection), "apex not or rather indistinctly crystalliferous", cheilocystidia rather frequent, similar to pleurocystidia, paracystidia abundant, clavate to pyriform, colorless, thin-walled; caulocystidia (almost) completely absent, extreme apex of stem with "narrow zone of undifferentiated to somewhat differentiated caulocystidioid hairs", (Kuyper for var. lacera, but he included var. heterosperma as synonym) extremely variable in size and shape, total range in size 5.5-15.5 x 4-6.5 microns, occurring in approximately four size categories, 5.5-6 x 4-4.5 microns, 8-9 x 5 microns, 10-11 x 4.5 microns and 12-15.5 x 4.5-6.5 microns, varying in shape from round to ovate, oval, kidney-shaped, inequilaterally almond-shaped, nearly cylindric, to the usual Boletus-like outline of the normal spore of I. lacera, (Grund for var. heterosperma), spores 8-13.5 x 5.5-7.5 microns, elliptic to long almond-shaped, (Phillips for var. heterosperma), spores 6.5-17 microns long, variable in shape, (Cripps for var. heterosperma)

Spore deposit:
snuff brown (Phillips), brown (Cripps), dark brown (Miller), dark brown (Buczacki)

Notes:
Some of the records may be Inocybe lacera var. helobia, for which the current name is Inocybe helobia, on the online Species Fungorum and on Mycobank, both accessed Nov 6, 2020. There are numerous collections from BC as var. lacera and as var. helobia by O. Ceska at the University of British Columbia. There is also a collection of Inocybe var. rhacodes by O. Ceska from British Columbia at the University of British Columbia. Inocybe lacera is widespread in North America and Europe, and found at least ID, MT, (Cripps(1) for var. lacera), WA (Matheny(5) (variety not specified)), and CA (Nishida(2) (variety not specified)). Kauffman(4) gives distribution of I. lacera (Fr.) P. Karst. (variety not specified) as New England and Canada to VA, AL, and MI, WA, OR, and Europe. Kuyper(1) examined collections of I. lacera var. lacera from NS, MI, Austria, Czechoslovakia, Denmark, Finland, France, Germany, Italy, Netherlands, Sweden, and the United Kingdom (England, Scotland).

EDIBILITY

no (Phillips)

Synonyms and Alternate Names:
Inocybe carbonaria Velen.
Inocybe demitrata Velen.
Inocybe mammosa Velen.
Inocybe mitracea Velen.
Inocybe moravica Hruby
Inocybe pallescens Velen.
Inocybe rhacodes J. Favre (of Order Agaricales)