Amanita phalloides, most commonly known as death cap mushroom, is a widespread toxic mushroom. It’s responsible for about 90% of mushroom related deaths worldwide, due primarily to it’s potent toxins, varied appearance and a host of edible lookalikes.
Death Cap 101
Death cap mushrooms , like many amanitas, start life small and egg shaped. As it grows taller, the cap separates from the ring and begins to flatten out. Caps can be pretty large, ranging from about 2″ to 6″ across. Death cap colors vary greatly in shades of green, bronze and white. It’s colors are usually paler after rainfall. The cap is often sticky to the touch and easy to peel, which is a feature in many edible fungi. In spite of it’s serious risk to human health, it’s flavor is said to be pleasant.

Death cap causes most of it’s havoc in Europe, where it is found from Scandinavia to Ireland to Italy. Many of death cap’s lookalikes are also found in this range. Additionally, death cap can be found in South America, North America, North Africa, Australia and West Asia.
Death Cap Camouflage
What feels devious about the death cap, is it’s resemblance to a number of edible mushroom varieties. Straw mushrooms, field mushrooms, Caesar’s mushrooms, puffballs and a variety of green Russula species, to name a few.

Above are death caps at various stages of their growth. Below are 8 mushrooms, one is a death cap and the other 7 are edible lookalikes. Can you spot the deadly mushroom?
















So, How Toxic is the World’s Deadliest Mushroom?
It only takes about 7g, or half a cap, of Amanita phalloides to kill an adult human. Death cap’s toxicity is is the result of multiple toxins, however most are destroyed with heat. The exception, and main reason for death cap’s 10 to 30% mortality rate, is amatoxin. Amatoxin is found in the mushroom genera Amanita, Galerina, Lepiota and Conocybe. It works by disrupting RNA, resulting in cell death. When ingested, amatoxin is first absorbed by the liver where it’s prevents the organ from repairing itself. The liver may disintegrate from this damage. From there amatoxin travels through the blood stream, affecting other organs. Death from amatoxin is most often due to liver or heart damage. Symptoms of death cap poisoning usually begin within 6 to 12 hours of ingestion. Symptoms include headaches, shortness of breath, coughing, insomnia, diarrhea and back pain. There are some reports of irritation after contact with skin, but amatoxin itself does not absorb into the skin. While the flesh of this mushroom is highly toxic and ingesting or inhaling it can make you very ill, the spores contain only 3% of death cap’s toxins. Many older field-guides contain anecdotes of death cap poisoning from spores, however the scientific consensus is that death from these spores is very unlikely.
While it’s impossible to verify historical mushroom identifications, there are a number of notable figures of the past whose deaths are suspected to be the result of death cap poisoning. This list includes Roman Emperor Claudius, Pope Clement VII, Tsaritsa Natalia Naryshkina, and Holy Roman Emperor Charles VI. While each of these deaths sent shockwaves through their respective homelands, Charles VI’s death had particularly catastrophic results. His untimely death led to the War of Austrian Succession, the estimated casualties of which are 750,000 from 7 different forces. Famed French philosopher Voltaire noted “this dish of mushrooms changed the destiny of Europe.”
While many of us were raised to fear mushrooms, only 15 to 20 varieties are capable of killing a human being. Death cap is by far the most dangerous, but luckily, with a little bit of knowledge and a healthy dose of caution, they are avoidable. Happy foraging!
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