Ontario is home to some bizarre specimens from the kingdom Fungi, with everything from species that bleed to others that can parasitize and control hosts' minds.

So it really shouldn't come as an earth-shattering surprise to hear that the province is also home to a species of mushroom that drips black ink and can turn alcohol into a lethal poison.

Coprinopsis atramentaria, commonly known as the common ink cap, can be found in a broad distribution across the globe that spans much of North America, including most of southern Canada and the entirety of Southern Ontario.

You've probably already seen them growing wild on lawns or in parks and thought nothing of them, measuring just 3-10 cm in diameter, with greyish or brownish-grey caps.

As the name suggests (its scientific name is derived from the Latin word atramentum, which translates to "ink"), the ink cap is known for its ability to ooze a black liquid when picked or disturbed, which was once used as a form of ink before modern inks were produced.

But the species' ink-producing ability isn't even the most fascinating thing about this mushroom.

The common ink cap is a rare example of a mushroom considered both edible and poisonous. And if that sounds nonsensical, you're just going to have to stop and hear me out for a minute.

If you were to consume a common ink cap (a stern reminder to always do extensive research or ask an expert before eating a random mushroom found in the wild), you'd probably describe the flavour as mild and earthy, and maybe even pleasant.

However, if you were to consume a common ink cap before or after having a few drinks, this mushroom hides a sinister secret that could cost you your life. Thanks to high concentrations of a mycotoxin known as coprine, the ink cap becomes poisonous when mixed with alcohol.

Next, ink caps! This is a family that contains a bunch of cool mushrooms that turn to black ink as they age (or after they are picked). Some have a toxin called coprine that stops you from beign able to metabolize alcohol (but shaggy manes don't). And the ink is useable! pic.twitter.com/qHHssyP3Dd

— Gnome Anne is an island (@annethegnome) October 8, 2024

Together, coprine and alcohol combine to heighten the body's sensitivity to ethanol, which causes an illness known as "coprinus syndrome."

The mechanism behind this toxicity works not unlike disulfiram, a drug commonly prescribed to patients recovering from alcoholism.

C. atramentaria's tendency to cause an acute reaction with alcohol has earned a colloquial name for the mushroom, "tippler's bane."