mushroom poisoning, fungal poisoning caused by ingestion of certain mushrooms (fungal organisms), most commonly Amanita phalloides and Amanita muscaria and related species. Symptoms, caused by toxic peptides, may include severe abdominal pain, vomiting, cold sweat, diarrhea, and excessive thirst; they appear 8 to 12 hours after ingestion. Damage occurs largely in the liver and kidneys. Some mushrooms contain substances that produce hallucinatory states, e.g., Psilocybe mexicana (see hallucinogenic drug; ergot). Occasional outbreaks of poisoning from eating canned mushrooms are not caused by poisonous mushrooms but by botulism resulting from improper canning methods.