Common Ink Cap

Measuring 3–10 centimetres (1+1⁄4–4 in) in diameter, the greyish or brownish-grey cap is furrowed, initially bell-shaped, and later more convex, splitting at the margin. It melts from the outside in. The very crowded gills are free; they are white at first, then grey or pinkish and turn black and deliquesce. The stipe measures 5–17 cm (2–6+3⁄4 in) high by 1–2 cm thick, is grey in colour, and lacks a ring. In young groups, the stems may be obscured by the caps. The spore print is black and the almond-shaped spores measure 8–11 by 5–6 μm. The flesh is thin and pale grey in colour.

Coprinopsis atramentaria occurs across the Northern Hemisphere, including Eurasia and North America, and has also been found in South Africa as well as Australia, where it has been recorded from such urban locations as the Royal Botanic Gardens in Sydney and around Lake Torrens. Like many ink caps, it grows in tufts. It is commonly associated with buried wood and is found in grassland, meadows, disturbed ground, and open terrain from late spring to autumn. Fruiting bodies have been known to push their way up through asphalt and even tennis courts. It is also common in urban areas and appears in vacant lots, and tufts of fungi can be quite large and fruit several times a year. If dug up, the mycelium can often be found originating on buried dead wood.

The mushrooms are considered edible when young, but consuming them within a few hours of alcohol results in disulfiram-like symptoms. This interaction has only been known since the early part of the 20th century. Symptoms include facial reddening, nausea, vomiting, malaise, agitation, palpitations, and tingling in limbs, arising five to ten minutes after consumption of alcohol. If no more alcohol is consumed, they will generally subside over two or three hours. Symptom severity is proportional to the amount of alcohol consumed, becoming evident when blood alcohol concentration reaches 5 mg/dl, and prominent at concentrations of 50–100 mg/dl. Disulfiram has, however, been known to cause myocardial infarction (heart attack). The symptoms can occur if even a small amount of alcohol is consumed up to three days after eating the mushrooms, although they are milder as more time passes. Rarely, a cardiac arrhythmia, such as atrial fibrillation on top of supraventricular tachycardia, may develop. Because of these effects, in some cases, the mushroom has been used to cure alcoholism. The fungus contains a cyclopropylglutamine compound called coprine. Its active metabolite, 1-aminocyclopropanol, blocks the action of an enzyme, acetaldehyde dehydrogenase, which breaks down acetaldehyde in the body. …