Glistening Ink Cap Mica Cap Shiny Cap
The glistening ink cap or mica cap is a gill mushroom belonging to the Coprinellus genus. They are saprobes that grow in tight clusters on stumps or at the base of dead or dying trees. You may also find them terrestrially as they feed on woody debris buried under the soil. A commonly widespread species and no stranger to urban habitats. Typically found in early Spring, but may appear all year round if winters are mild.
Cap Features (Pileus)
When young the caps are a tan color and obtusely conical (slightly cone-shaped). As they mature they become tawny and campanulate (bell-shaped). The surface of the cap usually contains granular remnants of the universal veil. These salt-like granules glisten in the light giving the mushroom its common name. However, they can wash away by rain. The cap margins are plicate (pleated or umbrella-like ) and extend the majority of the cap. After spore dispersals, mica caps go through deliquescence—a process of deterioration where the caps appear to melt away in an inky black goo. As deliquescing, the margins will appear eroded, split, and form a revolute (roll upwards) shape. Finally, the cap will completely dissolve.
The gills are even and closely spaced. The are pale-brown when young and eventually turn black. Even appearing purplish in the right light. They are adnexed (narrowly attached to the stem), broad and fragile. During deliquescence, the gills are first to dissolve.
The stems are fragile, equal, and hollow. White to somewhat tan and slightly fibrous but appear smooth to the naked eye. There is no indication of an annulus (veil) or ring zone.
The spores are black. If taking a spore print, do not wait too long because the cap will turn into a puddle of black inky goo.
A cross-section reveals a straight shaped margin on young specimens. As the mica cap matures the shape will become revolute (roll upwards). The flesh of the cap is cream and differs from the white flesh of the stem. Which is unique to Coprinellus micaceus as the majority of the Coprinellus genus have consistent flesh colors throughout the mushroom.
Can you Eat Coprinellus micaceus?
While some sources say younger specimens are considered edible, I would avoid the risk. Many species in the Coprinellus genus contain a mycotoxin called coprine. It inhibits the body from metabolizing alcohol. If you dare to consume a mica cap, do not drink alcohol for around 72 hours before or after.
Please Check Other Sources For Identification
Coprinellus micaceus Photos
- raremushrooms.com - Mica Caps
- Wikipedia - Mycotoxin: Coprine
- Coprinus syndrome