It is commonly called the Mica Cap. C. micaceus is one of the inky caps, so called because of the way the gills digest themselves (deliquesce) to release spores, leaving a black residue that resembles ink.
The pileus of C. micaceus is oval shaped when the mushroom is young and becomes convex as it ages. The size ranges from 2-5 cm (.75-2 in). Small, shiny white, granular scales can be found on the pileus when the mushroom is young. The name of the mushroom derives from these granular scales, which look like the mineral mica (Also, “mica” in Latin means shiny). The pileus ranges in color from yellowish to honey brown to amber.
Gills are attached to nearly free and very crowded. The color of the gills starts as white to very light gray when young and becomes purple to black and inky with age as the gills deliquesce.
The stipe of this mushroom ranges from 2.5-8 cm (1-3 1/8 in) long and 2-5 mm (1/8-1/4 in) thick. The stipe is white, smooth, and hollow.
The spore print of this mushroom is black. The spores are sized 7-10 um X 4-5 um. Microscopically, the spores are grayish to pale black, elliptical and smooth, with an apical pore.
C. micaceus can be found scattered or densely packed in groups. This mushroom grows on decaying wood. It is a very common mushroom to find. C. micaceus grows most commonly from April to October. It can be found in both urban lawns and forests.
This mushroom is thought to be edible but mostly flavorless.
Also known as Coprinus micaceus. The genus Coprinus was split up based on many microscopic features.