Coprinus

Genus of about 100 species of capped fungi, in the family Coprinaceae in the class Basidiomycetes, known as the ink caps. C. comatus, the shaggy ink cap or lawyer's wig, is a common species, edible when young. As it grows older the cap turns to a black liquid as it starts to decay. The genus takes its name from the common ink cap C. atramentarius, whose ageing caps were formerly used for making ink.