Summary:
Also listed in Veined category. Features include a small gray spathulate to kidney-shaped cap, close to subdistant gray fold-like to gill-like gills, short lateral stem, and habitat on ground or among plant debris.

Cap:
0.6-3.5cm across, obovate to spathulate, dimidiate, kidney-shaped, (or rarely nearly cyathiform), submembranous, the surface usually depressed, margins incurved at first, often uneven or undulate, later somewhat scalloped, margin occasionally lobed or incised; hygrophanous, "livid-gray or grayish-brown" (Peck 1886), "fuscous to Chaetura drab" (Hesler, 1933), or grayish sepia to pale mouse gray; moist to dry, initially opaque but later translucent, sometimes rugose, sometimes whitish-pubescent centrally, striate, (Redhead), 0.8-2cm across, gray, silky, +/- semicircular, (Moser), up to 2cm across, spathulate or kidney-shaped, lobed; gray; felted, (Courtecuisse)

Flesh:
colored as cap (Redhead), thin; grayish, (Buczacki)

Gills:
variable, often thick when young, suggesting Cantharellus, later thin and gill-like, adnate to decurrent, moderately spaced to subdistant, irregularly with 2 or 3 tiers of subgills, occasionally forked; colored as cap or paler; occasionally interveined, (Redhead), gray (Moser), close; gray, (Courtecuisse)

Stem:
up to 1.8cm long, 0.5cm wide, "attached either by a weft of whitish mycelium and either pendant or lateral or with stem-like broad plug of whitish to grayish tissue and perpendicularly or clinally ascending, sometimes pubescent to strigose", (Redhead), 1-3cm x 0.3-1cm, gray-whitish, (Moser), short, lateral, pubescent, (Courtecuisse)

Odor:
not distinctive (Redhead)

Taste:
not distinctive (Redhead)

Microscopic spores:
spores 5-9 x 4.2-5.5 microns, variable in shape, often predominantly nearly round or broadly obovoid, but also sometimes mostly elliptic, or with intermediate forms, smooth, thin-walled, inamyloid, colorless; basidia 4-spored, clavate, clamped, nearly colorless or in scattered individuals with fuscous sordid cellular contents, (Redhead), spores 6-8 x 3-4.5 microns, elliptic, (Moser), pleurocystidia and cheilocystidia absent; clamp connections present, (Watling)

Spore deposit:
white (Buczacki)

Notes:
Redhead examined collections of Arrhenia acerosa from BC, NS, ON, CA, MI, NY, TN, Argentina, Czech Republic, Sweden, and the United Kingdom. It is also found elsewhere in Europe including Switzerland (Breitenbach) and Britain/Ireland (Buczacki).

EDIBILITY

Synonyms and Alternate Names:
Leptoglossum acerosum (Fr.) M.M. Moser