What is the most deadly mushroom to humans?

What is the most deadly mushroom to humans? The answer is Amanita phalloides, commonly called the death cap. It is widely regarded as the deadliest mushroom because it causes the majority of fatal mushroom poisonings worldwide. The mushroom is especially dangerous because it can resemble edible species, including Caesar's mushroom and the straw mushroom.

Death caps contain amatoxins, which primarily damage the liver and can also harm the kidneys. These toxins are thermostable, meaning cooking, freezing, or drying does not make the mushroom safe. Symptoms may be delayed for 6–12 hours, and an apparent period of improvement can occur before severe organ damage develops.

Amanita phalloides originated in Europe but has been introduced to other regions, often alongside imported broad-leaved trees. Its cap color can vary from greenish to nearly white, so color alone is not a reliable identification method. Historical poisoning theories have even implicated the death cap in the deaths of Roman Emperor Claudius and Emperor Charles VI.