Amanita Muscaria - The Fly Agaric Mushroom Amanita Muscaria, Commonly Known As The Fly Agaric Or Fly Amanita, Is A Poisonous And Psychoactive Basidiomycete Fungus, One Of Many In The Genus Amanita. Native Throughout The Temperate And Boreal Regions Of The Northern Hemisphere, Amanita Muscaria Has Been Unintentionally Conveyed To Many Countries In The Southern Hemisphere, Generally As A Symbiont W Photo