Coprinopsis atramentaria - Common Inkcap

Coprinopsis atromentaria - Common Inkcap

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

From tree stumps or buried wood of deciduous hardwood trees, Coprinopsis atramentaria (syn. Coprinus atrmentarius), the Common Ink Cap, arises in small clumps from spring until early winter. It is poisonous when consumed in conjunction with alcohol, and the effects are sometimes severe. It is therefore unwise to eat these inkcap mushrooms if alcohol has been consumed during the three days before a meal or is likely to be consumed at any time during the three days afterwards.

Note: inkcap is sometimes written as ink-cap or ink cap, and in the USA the terms inky cap or inky-cap are used.

Identification guide

Cap	At first egg-shaped without veil fragments, the cap later expands to become bell-shaped with a slight umbo before deliquescing from the margin. Grey or grey-brown before turning black, caps attain a diameter of 3 to 7cm.
Gills	The free, crowded gill are white at first, turning brown and then black before autodigesting.
Stem	White with reddish-brown fibrils towards the base; 8 to 15mm diameter and 5 to 12cm tall.
Spore print	Black.
Odour/taste	Not distinctive.
Habitat	On or beside stumps (usually hardwood); also beside woodland footpaths and at the base or trees in parks and gardens..
Season	May to November.
Occurrence	Frequent.
Warning!	Poisonous if consumed either with or a day or two before/after alcohol.
Similar species	Coprinellus micaceus occurs in similar habitat but is redder and has mica-like veil fragments on the surface of the cap.