Coprinellus amphithallus
Coprinellus amphithallus is a species of mushroom in the family Psathyrellaceae. It was first described by mycologists Morten Lange and Alexander H. Smith in 1953 before being transferred to the genus "Coprinellus" in 2001. Description. The cap is tall, and initially sharply conical in shape, but later expands to become bell-shaped ("campanulate"). The margin of the cap curves upwards as the mushroom ages. The gills are narrow, and spaced close together. They have an adnate attachment to the stipe, and become black in color before dissolving ("deliquescing"). The stipe is by thick, hyaline to whitish. Initially it  is "pruinose" (with a very fine whitish powder), but later becomes smooth. The spores are cylindrical and tapering ("terete"), and tend to vary in size, with dimensions ranging from 11.2 to 15.6 by 6.2–8.3 µm. The spore-bearing cells, the basidia, are all 2-spored. Habitat and distribution. This fungus was discovered growing in rich, moist soil. It is known from Denmark and the USA.