Death Cap Mushrooms – The World’s Deadliest Fungi

As deadly as the name suggests, the Death Cap mushroom (Amanita phalloides) reigns supreme as the most deadly mushroom in the world. It is single-handedly responsible for 90% of all mushroom deaths, worldwide.

Where Will You Find Death Cap Mushrooms?

Death caps can be a fairly common find amongst the moist undergrowth of forest and woodland floors. Their fruiting season is fairly wide too, and you can usually find them from July until November, and possibly into December if the weather is mild.

The species is native to Europe, but through the trade and transportation of certain tree species, it is now found on all continents except Antarctica. Whilst they are highly poisonous to humans, some smaller mammals like rabbits and squirrels have been known to eat death cap mushrooms without any ill effect. Like other fungi, death cap mushrooms also provide a valuable ecological role by releasing nutrients back into the soil.

Why are Death Cap Mushrooms Poisonous?

Death cap mushrooms contain amatoxins and phallotoxins, with amanitin usually the most potent. It’s a poisonous substance that is not destroyed by cooking, so these mushrooms shouldn’t be eaten under any circumstances. Depending on their size, even half a cap of a small mushroom could be enough to kill. So mushroom foragers know to follow a very strict identification process when they’re searching for edible mushrooms, although accidental deaths do sadly occur.

What are the Symptoms of Death Cap Poisoning?

Usual poisoning symptoms begin up to 24 hours after consuming a death cap. Symptoms involve abdominal cramps, vomiting, and diarrhea, but internal damage begins hours after consumption. The amanitin inhibits the production of protein within the liver, which can begin to cause irreparable damage to other organs, leading to organ failure and death. Treatment is possible, but the likelihood of survival depends on how much time has passed since consumption. Some individuals who have survived death cap poisoning only survived because of an emergency liver transplant.

What Does a Death Cap Look Like?

Death caps are fairly inconspicuous mushrooms. They have no bright colors or any unique textures or shapes. As they first emerge from the ground they are fully white, before the cap forms and turns an off-white to light olive green color. The gills are generally white, with the stem having a more off-white color. When fully formed the domed cap can often reach a diameter of 15cm. 

Similar Edible Species

A young death cap mushroom can resemble an edible puffball mushroom before its cap fully forms. So some poisoning instances occur when novice foragers mistake death cap mushrooms for the edible puffball. 

There have also been occasions where immigrants have mistaken death cap mushrooms for a familiar edible mushroom from their home country. There was a notable case of a Korean family in the US mistaking death caps for straw mushrooms (Volvariella volvacea).

Cultural Symbolism and Mythology

The death cap has been known as a poisonous mushroom for centuries. Records from many different cultures have recognized death caps as a mushroom that should be avoided.

It’s often one of the very first things we learn as children out in nature, and the reason adults are constantly reminding their children — “Don’t touch/eat any mushrooms, they could be poisonous!”. Even in a world where we forage so much less and depend solely on large-scale production and farming. Curious children always need this inherent knowledge to be passed down to them. A higher percentage of accidental death cap poisonings happen in children, so parents are right to be cautious.

The death cap is also able to produce a natural phenomenon known as a ‘fairy ring’, with roughly only 60 mushroom species known to create these ‘patterns’. They are often linked with folkloric tales of witchcraft and superstition, with some cultures believing they shouldn’t be entered and others believing they are marks left by dancing fairies.

Famous Deaths & Notable Victims

A number of historical accounts note that the Roman empress Agrippina the Younger may have poisoned her husband, Emperor Claudius, with death cap mushrooms. They were supposedly mixed into a meal that included other mushrooms, and he died shortly afterwards.

Another notable victim is Charles VI, Holy Roman Emperor and a member of the Austrian monarchy. After eating a dish of sautéed mushrooms, he experienced symptoms that match those of death cap poisoning, and he died 10 days later on 20th October 1740 aged 55. It is unknown if the mushrooms were picked accidentally, or if his death was a successful assassination attempt.

Conclusion

An incredibly deadly mushroom with a far-reaching history of some fairly notable poisonings. Along with its relative, the Destroying Angel mushroom, it’s one of the mushrooms responsible for the majority of accidental mushroom foraging deaths.