Death Cap vs Ink Cap Mushroom: How Their Poisons Differ

The death cap (Amanita phalloides) and the common ink cap (Coprinopsis atramentaria) are both poisonous, but in completely different ways. The death cap's amatoxins destroy the liver whether the mushroom is raw or cooked, and Wikipedia estimates that half a mushroom can kill an adult. The ink cap's coprine does nothing noticeable on its own; it causes a violent reaction only when alcohol is drunk, from minutes after the drink and for up to three days after the meal (Wikipedia).

They turn up in the same searches because both appear on popular lists of poisonous mushrooms, such as the seven-species guide from Field & Stream republished by Popular Science in March 2020, and both grow in towns: ink caps in lawns and vacant lots, death caps under planted host trees.

• Cap. Death cap: 5 to 15 cm, pale green, yellowish green, olive, bronze or, in one form, white (Wikipedia). Ink cap: 3 to 10 cm, grey to brownish grey, furrowed, bell-shaped at first, later splitting at the edge (Wikipedia).
• Gills. Death cap: white, crowded and free of the stem. Ink cap: whitish, turning grey or pinkish and then black, finally dissolving into black 'ink' (Wikipedia; MushroomExpert.com).
• Stem. Death cap: a floppy skirt-like ring 1 to 1.5 cm below the cap and a ragged, sac-like white volva at the base. Ink cap: 5 to 17 cm tall, 1 to 2 cm thick, grey to white, hollow, no ring (Wikipedia; MushroomExpert.com).
• Spore print. Death cap white; ink cap black.
• Habit. Death cap: from soil near oaks, beeches, chestnuts, birches, hornbeams, pines, spruces and other hosts (Wikipedia). Ink cap: in clusters on decaying wood, often from old roots around stumps (MushroomExpert.com), common in grassland, urban lots and even pushing through asphalt, late spring to autumn (Wikipedia).

Extremely. Wikipedia estimates that half a mushroom contains enough toxin to kill an adult and attributes about 90% of mushroom-related deaths each year to this species. The course it describes:

• Nothing for 6 to 12 hours after eating.
• Nausea, vomiting and diarrhoea, which settle within 2 to 3 days.
• A period of feeling fine that can last up to 72 hours.
• Liver and kidney damage from 3 to 6 days after eating; deaths typically 6 to 16 days after poisoning.

Modern mortality is given as around 10 to 30%, against 60 to 70% historically. Cooking, freezing and drying do not reduce the toxins, and survivors have described the taste as pleasant (Wikipedia). The Field & Stream guide republished by Popular Science gives a wider onset window of 6 to 24 hours. The full species page is death cap mushroom.

The poisonings described in these sources all come from eating death caps. Even so, Wikipedia reports that authorities advise against touching suspected death caps and strongly against putting them in the same basket as mushrooms meant for the table. Follow that advice: use gloves or a bag over your hand to remove one, wash your hands afterwards, and keep children and dogs away. If a child may have put any of it in their mouth, call Poison Control at 1-800-222-1222 at once.

No source used here clears it, and this site does not. Wikipedia says it is considered edible when young but that alcohol taken after eating it causes a reaction like the drug disulfiram (Antabuse): facial flushing, nausea, vomiting, malaise, agitation, palpitations and tingling in the limbs. The reaction starts 5 to 10 minutes after the drink and usually settles within 2 to 3 hours if no more alcohol is taken; rarely, heart rhythm problems such as atrial fibrillation develop.

The window is what catches people out. Wikipedia says alcohol drunk up to three days after the meal can still trigger it, more mildly as time passes, and Hong Kong's Centre for Food Safety uses 72 hours for inky caps. The Field & Stream guide puts it plainly: you could eat the mushroom, feel fine, have a drink a few days later and become seriously sick.

Most ink cap questions start with the shaggy mane, Coprinus comatus, a related ink cap that people look for in lawns. Three-way confusion is the risk:

• Shaggy mane. Tall, almost cylindrical white cap 6 to 20 cm high covered in shaggy scales, a loose ring low on the stem, black-brown spore print; Wikipedia says it does not cause the alcohol reaction.
• Common ink cap. Grey to brownish grey, smoother, furrowed, clustered on buried wood; Holden Forests & Gardens separates it from the shaggy mane by its lack of shaggy texture.
• Young Amanita. Wikipedia's mushroom-poisoning article records a case where immature Amanitas were mistaken for shaggy manes, and Holden Forests & Gardens pairs the shaggy mane with the destroying angel as a look-alike risk. A white spore print and a volva at the base point to Amanita, not to any ink cap.

Wikipedia's Coprinus comatus article also names the green-spored Chlorophyllum molybdites, responsible for most mushroom poisonings in North America, as a look-alike. See green-spored parasol.

Call Poison Control at 1-800-222-1222 (U.S.) right away, or your local emergency number. Do it now, before any symptoms: Poison Control warns that symptoms from poisonous mushrooms can be delayed for many hours. Keep any leftover mushroom for identification and note when it was eaten.

There is no home remedy. Hospital treatment described in the literature summarised by Wikipedia includes activated charcoal or gastric lavage, high-dose penicillin G, silibinin (from milk thistle), N-acetylcysteine and, in severe cases, liver transplantation. Speed matters: Wikipedia's mushroom-poisoning article reports mortality of about 10% for patients admitted almost immediately after eating amanitin-containing mushrooms, against 50 to 90% for those admitted 60 or more hours later. This page does not give medical advice.

Call Poison Control at 1-800-222-1222 and say that ink caps were eaten and whether any alcohol has been drunk since. The sources above describe the alcohol reaction window as up to three days (Wikipedia) or 72 hours (Centre for Food Safety, Hong Kong). Also ask for the identification to be checked: a mushroom eaten as an 'ink cap' could have been something else.

• The cap from above and from the side.
• The gills, and whether their edges are turning black or dissolving.
• The whole stem dug out, to show a ring, a volva or neither.
• A spore print: white points towards Amanita, black towards the ink caps.
• What it grew from: soil under a tree, a stump, or lawn.

Photograph it with MushroomLens and the app suggests what it may be. Use identification to know what to avoid, not what to cook.

Research and drafting for this page were assisted by AI and checked line by line against the sources listed below. Nothing on this page says a wild mushroom is safe to eat. If you find an error, tell us and we will correct it.