Common Inkcap
Coprinopsis atramentaria
The common inkcap is a saprobic fungus that thrives primarily on nutrient-rich soils or buried decaying wood. Its acorn-shaped, gray-brown cap features characteristic longitudinal furrows and later expands to a bell shape. A prominent feature is the self-digestion (autolysis) of the gills into a black spore-bearing ink. When consumed with alcohol, the mushroom is toxic due to the presence of coprine, which inhibits the breakdown of acetaldehyde.
Details
Identification
Gray, radially furrowed cap; white gills turning black and dissolving; white, hollow stem; caespitose (clustered) growth.
Social behavior
Usually grows in dense clusters (caespitose), with mycelia extensively networked in the soil.
Diet
Saprobic; obtains nutrients by decomposing dead organic matter, especially woody debris.
Overwintering
Overwinters as mycelium within the substrate (soil or wood).
Ecology
Ecological role
Important decomposer in the ecosystem, converting complex organic matter into inorganic nutrients.
Natural predators
Fungivorous insect larvae (e.g., fungus gnats), slugs.
Competitor species
Other saprobic fungi such as brittlestems or other inkcap species.
Ecosystem service
Nutrient cycle regulation and humus formation through decomposition of organic matter.
Threats
Intensive soil cultivation and large-scale sealing of green spaces.
Scientific profile
Profile
Distinguishing features
Bell-shaped, folded/grooved cap; gills turn black and deliquesce at maturity; toxic when consumed with alcohol due to coprine (Coprine syndrome).
Habitat
Anthropogenic sites such as parks, gardens, roadsides, as well as thickets and clear-cuts; prefers nitrogen-rich soils.
Reproduction
Sexual via basidiospores formed on the gills.