Full Size
Cap: 1-5 cm; obtusely conical to bell shaped or nearly spherical when young, expanding slightly (often to broadly bell-shaped) with age; dry; smooth to silky when young, often becoming finely hairy or prominently cracked with age; sometimes with a reticulate network of raised ridges; whitish, gray, brownish, brown, or reddish brown; sometimes developing olive discolorations; the margin hung with white, toothlike partial veil fragments, at least when young (check this feature in the field, since the fragments are easily shed in collection bags).
Gills: Attached to the stem, or pulling away it with maturity; close or crowded; grayish when young, but soon developing black areas and acquiring a mottled appearance; eventually black overall; with whitish edges.
Stem: 4-16 cm long; up to 5 mm thick; more or less equal; finely hairy; often brittle; colored more or less like the cap, but paler at the apex and darkening toward the base with maturity or on handling.
Spores: 11-18.5 x 7.5-12 µ; more or less elliptical, with a pore; smooth; dextrinoid; not discoloring in concentrated sulphuric acid. Basidia 4-sterigmate; abruptly clavate. Pleurocystidia absent. Cheilocystidia abundant; subcylindric, often subcapitate or capitate.
Habitat & Distribution: Saprobic; growing alone to gregariously in the dung of horses and cows; common; widely distributed in North America; spring, summer, and fall (and over winter in warmer climates).
Note: This species has been repoted to be active in the literature however I believe that is mostly based on misidentification or poor lab technique. Many collections have been eaten and found to be inactive, with no active collections that I am aware of.
