Death cap mushroom (Amanita phalloides) growing on a woodland floor. This is the most poisonous mushroom known. It grows in woodland, usually oak, in late summer and autumn throughout Europe and North America. Symptoms begin up to a day after the mushrooms are eaten, and usually start with stomach pains, vomiting and diarrhoea, which may last 24 hours or more. This is usually followed by an apparent recovery, but death occurs within a few days from liver and kidney failure. Treatment must begin very soon after ingestion to prevent death.