Common Inkcap
Poisonous 
Autumn 
Spring 
Summer 
This mushroom is known for causing severe poisoning when consumed with alcohol, but there are suggestions that it also has longer lasting health effects, therefore we moved it to the poisonous section and can’t recommend eating it. See more below.
| Mushroom Type | |
| Common Names | Common Inkcap, Tipplers Bane |
| Scientific Name | Coprinopsis atramentaria |
| Synonyms | Coprinus atramentarius |
| Season Start | Apr |
| Season End | Nov |
| Average Mushroom height (CM) | 10 |
| Average Cap width (CM) | 8 |
Cap
Shiny grey/brown or sometimes quite pink, smooth, darker in the middle and initially bell-shaped becoming furrowed and then splitting before deliquescing.
Gills
White and crowded turning to grey then black and deliquescing, melting to a black ink.
Stem
White to off white, smooth and leaving a skirt like ring near the base of the stem.
Flesh
White and thin turning grey/black before deliquescing.
Habitat
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 and the inedible but beautiful Magpie Inkcap.
Spore Print
Date brown. Almond shaped.
Taste / Smell
Mushroomy. Shouldn’t be ingested raw, causes poisoning when ingested with alcohol and we don’t recommend eating it in any circumstance. See more below under other facts.
Frequency
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.
8 comments for Common Inkcap
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”
I have discovered Common Ink Cap Mushrooms growing in my gravel. What animals are likely to eat them?
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.
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.
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?
I’m afraid I’m not sure. They are only toxic to humans when consumed with alcohol so the dog should be fine.
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.”
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).