Coprinus

About

Coprinus is a small genus of mushroom-forming fungi consisting of Coprinus comatus—the shaggy ink cap (British) or shaggy mane (American)—and several of its close relatives. Until 2001, Coprinus was a large genus consisting of all agaric species in which the lamellae autodigested to release their spores. The black ink-like liquid this creates gave these species their common name "ink cap" (British) or "inky cap" (American).

Summary from Wikipedia