Common Inkcap

Poisonous Poisonous
Autumn Autumn
Spring Spring
Summer Summer

This mushroom is known for causing severe sickness when consumed with alcohol, but there are also suggestions that it also has longer lasting health effects, therefore we have moved it to the poisonous section and can’t recommend eating it. See more below.

Mushroom Type
Common Names Common Inkcap (EN), Tipplers Bane, Cap Inc (CY), Czernidłak Pospolity (PL), Ráncos Tintagomba (HU)
Scientific Name Coprinopsis atramentaria
Synonyms Coprinus atramentarius
Season Start Apr
Season End Nov
Average Mushroom height (CM) 7-9
Average Cap width (CM) 5-7
Please note that each and every mushroom you come across may vary in appearance to these photos.


5-7 cm. Shiny grey/brown or sometimes quite pink, smooth, darker in the middle and initially bell-shaped becoming furrowed and then splitting before deliquescing.


White turning to grey then black and deliquescing, melting to a black ink. Very crowded and free of the stem.


7-9 cm long, 0.4-0.6 cm diameter. White to off white, smooth and leaving a skirt like ring near the base of the stem.


White and thin turning grey/black before deliquescing.


Growing from buried wood so can be found in mixed woodland and by the sides of paths.

Possible Confusion

Some of the other Inkcaps look superficially similar but its shape and smooth cap are quite distinctive identification features.
See the good edible Shaggy Inkcap (Coprinus comatus) and the inedible but beautiful Magpie Inkcap (Coprinopsis picacea), pictured.

Spore Print

Date brown. Almond shaped.

Taste / Smell

This mushrpoom should never be ingested raw, it causes poisoning when ingested with alcohol and we don’t recommend eating it in any circumstance. See more below under other facts.


Fairly common.

Other Facts

WARNING: The Common Inkcap causes severe poisoning if consumed with alcohol 48 hours either side of eating the mushroom. Even applying alcohol based aftershave after eating it can cause a reaction. It was still listed as edible in some guides if alcohol was avoided. Recent studies suggest that it contains toxins with a carcinogenic potential and some authorities advise it shouldn’t be consumed at all, therefore we can’t recommend eating it.

The black mess left after the mushroom deliquesces used to be used as ink after boiling with a little water and cloves, or urine.


9 comments for Common Inkcap

  1. DEAN says:

    What source are you referring to “Recent studies suggest that it contains toxins with a carcinogenic potential and some authorities advise it shouldn’t be consumed at all”

  2. Barbara Wilkinson says:

    I have discovered Common Ink Cap Mushrooms growing in my gravel. What animals are likely to eat them?

    1. Eric Biggane says:

      Most mushrooms are consumed by slugs, snails, beetle larvae, other insects and sometimes by squirrels and other mammals, I’m not sure exactly what eats the Common Ink Cap but toxins that affect humans don’t usually cause any problems for invertebrates so I would have thought they are eaten by any of the above.

  3. Lugnut says:

    I see these in Michigan near Detroit in October on woodlines near warehouses as I am a trucker. They grow where the grass is cut close to the woods.

  4. Sheila says:

    My dog has eaten a few of these without my knowledge of them growing in our yard. Is species of mushroom toxic if consumed by dogs?

    1. Eric Biggane says:

      I’m afraid I’m not sure. They are only toxic to humans when consumed with alcohol so the dog should be fine.

  5. Jesse Clark says:

    Could you please share a source for the “authorities” you mention that claim that these contain carcinogenic compounds?

    The only data point that I have been that is remotely similar is a study from 1979 that cited findings of:
    “In dogs, oral administration of benzcoprine for 1 month caused impaired spermatogenesis, degeneration of germ cells and a decrease in the testicular weight.”

    1. Attila Fodi says:

      Common inkcap (Coprinopsis atramentaria) contains coprine, which is responsible for its Antabuse- or disulfiram-like effect. The source of its Haddad and Winchester’s Clinical Management of Poisoning and Drug Overdose (4th Edition), published by Elsevier Health Sciences in 2007. I don’t have to book with me at the moment, so I can’t give you the exact page where you can find it, but it is from Chapter 23. (It might be not the best or the most up-to-date source, but it is not our call to make. We are foragers, not clinical toxicologists, and Elsevier Health Sciences is a publisher with good reputation).

  6. Emma says:

    I have one growing in my seedling pot. Came here to identify it, other source don’t mention if it’s poisonous. Thanks wild food uk

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