A number of potentially poisonous mushrooms are superficially similar in appearance but do not match all the key characteristics of this species. The similar-looking but not-recommended Coprinopsis variegata
differs in that the cap is scaly and oval-shaped when young. The less common Coprinopsis romagnesiana
is similar in that it clusters at the base of trees, also has blackish spore print, and also has a cap that becomes inky. However, it differs in that the cap has a tan ground color as is covered with brown, appressed scales. In terms of edibility and interactions with alcohol, it is similar to this species. The edible Coprinellus disseminatus
differs in that it is smaller (under 2 cm broad) and does not become inky when old.
See also Coprinellus micaceus