(genus Coprinus), any member of a group of about 100 cosmopolitan mushroom species belonging to the order Agaricales. They are so called because, after spore discharge, the cap disintegrates into an inklike liquid that has been used for writing. They grow on wood and dung. The caps of C. atramentarius and C. comatus (shaggy mane, or shaggy cap) are edible when young, before the gills turn black.

From the Encyclopedia Britannica