Mica Cap

Photo of mica cap cluster, bell-shaped, brown, capped mushrooms
Safety Concerns
Scientific Name
Coprinellus micaceus (formerly Coprinus micaceus)

Bell-shaped, tawny brown, radially lined cap; inky gills. Grows in clusters around stumps or on wood debris. April–October. Cap egg-shaped, becoming bell-shaped; tawny brown, darkening with age; covered with shiny, micalike granules when young; with age, cap and gills become inky and liquefy. Gills broad; spacing close; white, becoming dark brown, then inky black; gills attached. Stalk thick; white, discoloring to buff; smooth, sometimes like felt; fragile, hollow. Universal veil leaves shiny, micalike granules on cap when young, but these disappear quickly. Spore print dark brown to black. Spores magnified are elliptical, smooth, with small pore at tip.

Lookalikes: The alcohol inky (Coprinopsis atramentaria) is fleshier and grayish.

Other Common Names
Common Inky

Cap Width: ½–2 inches; stalk length: 1–3 inches; stalk width: ⅛–¼ inch.

Where To Find
image of Mica Cap Common Inky distribution map


Grows in clusters around stumps or on wood debris, occasionally on buried wood (causing them to look like they're growing from the soil).

Edible, when young and fresh, and before the cap begins to dissolve into inky liquid (deliquesce). Don't try to save these for later in the refrigerator; it won't keep them from liquefying. Cook your mica caps soon after collecting.

Life Cycle

Mushrooms exist most of the time underground or within rotting logs as a network of cells (mycelium) connected to whatever it is they take nourishment from, in this case, rotting wood. When ready to reproduce, the mycelium sends up the mushroom, which is the reproductive structure. Spores are produced in the gills and are released to begin new mycelia elsewhere. In inky caps, the spores are distributed when the cap liquefies.

Coprinoids or inky caps have black spores that turn wet and “inky” with age. Eventually the caps will autodigest (dissolve into nothing). A black ink can be made by boiling the dark, liquifying caps with a little water and cloves.

This is one of the many fungus species that live on decaying plant materials. It and other such saprobic fungi play an incredibly important role in breaking down the tough materials plants are made of and returning those nutrients to the soil.

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Similar Species
About Mushrooms in Missouri

Mushrooms are a lot like plants, but they lack chlorophyll and have to take nutrients from other materials. Mushrooms are neither plants nor animals. They are in a different kingdom — the fungi. Fungi include the familiar mushroom-forming species, plus the yeasts, molds, smuts, and rusts.

Always be cautious when eating edible mushrooms. Be absolutely sure of the ID, and only eat a small amount the first time you try it to avoid a reaction..