 A fatal dose has been calculated as 15 caps . <unk> from this fungus A. muscaria have been reported in historical journal articles and newspaper reports , but with modern medical treatment , fatal poisoning from <unk> this mushroom is extremely rare . Many older books list Amanita muscaria as " deadly " , but this is an error that implies the mushroom is more toxic than it is . The North American Mycological Association has stated there were no reliably documented fatalities from eating this mushroom during the 20th century . The vast majority ( 90 % or more ) of mushroom poisoning deaths are from eating the greenish to yellowish " death cap " , ( A. <unk> ) or perhaps even one of the several white Amanita species which are known as destroying angels . 
