Coprinellus domesticus, commonly known as the domestic inky cap,[2] or firerug inkcap,[3] is a species of mushroom in the family Psathyrellaceae.

[4] The firerug inkcap gets its name from the bright orange carpet of hyphae grown around the mushroom.

[5] The covering is known as an ozonium, which resembles an aboveground mycelium.

[5] The ozonium is not always present, however, and can also grow in the absence of any mushrooms.

[6] Additionally, Coprinellus radians is identical in every aspect except for its larger spore size.