# Death cap (Amanita phalloides)

**Amanita phalloides**

**Known today as.** A greenish, white-gilled mushroom of oak and beech woods, now spread worldwide.

Kind: Fungus  
Poisoning: Amatoxin poisoning (https://thethinkingpress.org/materia-medica/poisons/amatoxin)  
Deadly: yes

> **Deadly.** Half a cap can kill an adult; cooking does not destroy the toxin.

## What was it used for?

None, though its alpha-amanitin is now on trial in drugs against cancer.

## What does modern science say?

Its amatoxins stop the liver’s cells from making proteins. Symptoms are delayed six to twelve hours, then seem to pass before the liver fails. It causes most of the world’s mushroom deaths. Silibinin, from milk thistle, is among the treatments.

## Pharmacognosy and toxicology

- **alpha-amanitin**: 
- **beta-amanitin**: 
- **phalloidin**: not absorbed from the gut

**Mechanism.** Inhibition of RNA polymerase II.

**Dose.** Under 0.1 mg of -amanitin per kilogram: half a cap.

**Standing.** None. The cause of nine-tenths of fatal mushroom poisonings.

## What lore surrounds it?

Tacitus and Suetonius report that the emperor Claudius was poisoned in a dish of mushrooms, a favourite of his; he died in AD 54, and Gordon Wasson suspected the death cap. The emperor Charles VI is said to have died in 1740 after a meal of mushrooms, of which Voltaire remarked that it changed the destiny of Europe.

## Sources

- Tacitus, *Annals* XII.
- Suetonius, *Life of Claudius*.
- Wikipedia, “Amanita phalloides,” en.wikipedia.org (read 2 October 2026).
- Wikipedia, “Amanita bisporigera,” en.wikipedia.org (read 2 October 2026).

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*Death cap.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/death-cap

Historical description, not medical advice.