Common Inkcap

Coprinopsis atramentaria

Toxic with alcohol

Also called alcohol inky, tippler's bane, inky cap.

The common inkcap is a gray-brown mushroom that grows in dense clusters on lawns and around stumps, with gills that dissolve into black ink. It contains coprine, which causes a sharp illness when alcohol is drunk in the days around eating it.

A dense clump of gray, bell-shaped common inkcaps with ribbed caps growing in grass

The tell

Gray-brown, finely lined, bell-shaped caps in tight clusters whose gills melt into black ink.

Field marks

What to look at

Cap, underside and stem show in a photo. The spore print does not, and it is often the deciding check.

Cap
Egg-shaped at first, opening to bell-shaped, gray to gray-brown, often with a few small brownish scales near the center. The surface is faintly lined or grooved from the edge inward, and the edge splits and blackens with age.
Underside
Gills free or nearly free, crowded, white at first, then gray, then black as they liquefy into ink.
Stem
White, smooth, hollow and fragile, with a faint ring-like zone near the base and no true ring.
Flesh
Thin, whitish to gray, turning black as the cap dissolves. Smell mild.
Spore print
Black.
Size
Cap 1 to 3 inches wide (2.5 to 7.5 cm); stem 2.5 to 6 inches tall (6 to 15 cm).

Where and when

Where and when it grows

Habitat
Lawns, gardens, parks, roadsides and urban ground, often at the base of stumps or over buried roots and wood.
Grows on
Buried or decaying wood and soil rich in organic matter.
Season
Spring through fall, usually after rain.
Range
Widespread across North America, especially in towns and on disturbed ground.

Lookalikes

What the common inkcap gets confused with

Each card says how to tell the two apart.

Edibility

What the field guides say

Toxic with alcohol

The common inkcap contains coprine, a compound that blocks the body's breakdown of alcohol in a similar way to the drug disulfiram. Field guides record flushing of the face and neck, a racing heart, nausea, vomiting and tingling in the hands when alcohol is drunk within about three days of eating it. Without alcohol, guides record no symptoms, which is why it is classed as toxic with alcohol rather than poisonous on its own.

This page states what field guides record. It is not advice to eat, taste or handle anything, and a photo cannot settle edibility. If someone has eaten a wild mushroom that may be toxic, call poison control (1-800-222-1222 in the US) right away, before symptoms start: the deadliest species act hours later.

FAQ

Questions about the common inkcap

Why is the common inkcap called tippler's bane?

It contains coprine, which stops the body from breaking down alcohol properly. Drinking alcohol within about three days of eating it causes flushing, a pounding heart, nausea and vomiting. The name refers to that reaction.

Is the common inkcap poisonous?

Field guides class it as toxic in combination with alcohol. The coprine it contains causes a disulfiram-like reaction when alcohol is consumed in the following days. Guides record no symptoms without alcohol.

What does a common inkcap look like?

It has a gray to gray-brown, bell-shaped cap with fine lines from the edge inward, on a white hollow stem. It grows in dense clusters, and the gills turn black and drip ink as the caps age.

Sources

Where these facts come from

  1. Coprinopsis atramentaria

    MushroomExpert.com

  2. Alcohol Inky

    Missouri Department of Conservation

  3. Coprinopsis atramentaria

    MykoWeb, California Fungi

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