Habitat: Singled to numerous, on horse or cow dung.

Spores: June-October

Conservation Status: Not of concern

Edibility: Hallucinogenic

Also found on dung is P. merdaria, which is similar, but has a dingy yellow to orange-brown or cinnamon-brown cap, and a veil which often forms a fibrillose annulus (ring) on the stalk. It is common also, and widely distributed. P. angustispora is a minute conical brown inhabitant of the Pacific Northwest; it grows on the dung of elk, sheep, etc.

Hallucinogenic

Cap: convex to broadly convex or flat; margin with whitish patches at first; smooth, dark reddish-brown, fading to grayish-brown. Gills: attached, nearly distant, broad; whitish to brown or purplish-brown. Stalk: whitish, darkening to brown, but not bruising blue. Veil: partial veil evanescent. pore print: purplish brown to nearly black; spores 11-14 x 6.5-8.5 microns, elliptical, smooth. Chrysocystidia absent on gills.

Sources: Lincoff, Gary. National Audubon Society Field Guide to North American Mushrooms. New York, Alfred A. Knopf, 1981. Arora, David. Mushrooms Demystified. Berkeley, Ten Speed Press, 1986.