Amanita phalloides, commonly known as the death cap, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Widely distributed across Europe, but introduced to other parts of the world since the late twentieth century, A. phalloides forms ectomycorrhizas with various broadleaved trees. In some cases, the death cap has been introduced to new regions with the cultivation of non-native species of oak, chestnut, and pine. The large fruiting bodies (mushrooms) appear in summer and autumn; the caps are generally greenish in colour with a white stipe and gills. The cap colour is variable, including white forms, and is thus not a reliable identifier.
Amanita phalloides
Death caps in French deciduous wood
A young death cap emerging from its universal veil
Young "death cap" mushrooms in Poland, with matchbox for scale
The genus Amanita contains about 600 species of agarics, including some of the most toxic known mushrooms found worldwide, as well as some well-regarded edible species. The genus is responsible for approximately 95% of fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The most potent toxin present in these mushrooms is α-Amanitin.
Amanita
A. phalloides, the death cap
A. caesarea (edible)
Amanita muscaria, commonly known as the fly agaric, contains the psychoactive compound ibotenic acid.