Psilocybin mushrooms, also known as psychedelic mushrooms, are mushrooms that contain the psychedelic compounds psilocybin and psilocin.Common colloquial terms include magic mushrooms and 'shrooms.ver 100 species are classified in the genus Psilocybe. Psilocybin mushrooms have likely been used since prehistoric times and may have been depicted in rock art and pre-Columbian historical materials in Mesoamerica. Many cultures have used these mushrooms in their religious rites and ceremonies.