Coprinopsis atramentaria

Pileus
Cap 3-8 cm broad, oval, becoming conic, finally campanulate in age; grey-brown, dry, with innate silky fibrils; disc darker, usually with small flattened scales; margin striate to corrugated, deliquescing towards the center; flesh thin, pallid.

Lamellae
Gills crowded, free, white, becoming pinkish-grey, blackening in age.

Stipe
Stipe 6-15 cm long, 1-2 cm thick, white above, greyish-brown below the ring, dry, hollow, equal to sometimes enlarged at the base; veil fibrillose, forming an evanescent, basal annulus.

Spores
Spores 7-11 x 4-6 µm, elliptical, smooth, with an apical germ pore. Spore print black.

Habitat
Solitary to clustered, in grass, often near rotting wood; fruiting from fall to spring, although specimens can be collected any month of the year that moisture is available.

Edibility
Edible, but not recommended unless alcoholic beverages are avoided for several days before and after ingestion. It contains a compound, coprine, that can cause nausea, facial flushing, and an accelerated heart beat when ingested with alcohol.

Comments
Coprinopsis atramentaria is recognized by its smooth to silky, greyish-brown caps, clustered habit, and deliquescing gills. It prefers disturbed habitats and thus is at home in the urban environment where it inhabits dirt parking lots, gardens, and grassy areas. Like its cousin, Coprinellus micaceus, it often fruits near buried wood. Coprinopsis atramentaria can be easily distinguished from Coprinus comatus which has a columnar-shaped, scaly cap, and from C. micaceus which a yellow-brown mica-flecked cap and is a smaller mushroom.