A psilocybin mushroom, also known as a psychedelic mushroom, is one of a polyphyletic group of mushrooms that contain any of various psychedelic compounds including psilocybin, psilocin, and baeocystin.
Common colloquial terms for psilocybin mushrooms include magic mushrooms, shrooms, and mush.
They are used mainly as an entheogen and recreational drug whose effects can include euphoria, altered thinking processes, closed and open-eye visuals, synesthesia, an altered sense of time, and spiritual experiences.
Biological genera containing psilocybin mushrooms include Copelandia, Gymnopilus, Inocybe, Mycena, Panaeolus, Pholiotina, Pluteus, and Psilocybe.
Over 100 species are classified in the genus Psilocybe.
Psilocybin mushrooms may have been used since prehistoric times.
They are possibly depicted in Stone Age rock art in Europe and Africa, and have a history of use in pre-Columbian Mesoamerica.
Some cultures have used these mushrooms in their religious rites and ceremonies.
Archaeological evidence suggests that psilocybin-containing mushrooms have been used by humans since prehistoric times.
It has been argued that prehistoric rock art near Villar del Humo, Spain, offers evidence that Psilocybe hispanica was used in religious rituals 6,000 years ago, Hallucinogenic species of the Psilocybe genus have a history of use among the native peoples of Mesoamerica for religious communion, divination, and healing, from pre-Columbian times to the present day. and depicting a mushroom strongly resembling Psilocybe mexicana was found in a west Mexican shaft and chamber tomb in the state of Colima.
Mushroom stones and motifs have been found in Guatemala. A Psilocybe species was known to the Aztecs as teōnanācatl (literally "divine mushroom" - agglutinative form of teōtl (god, sacred) and nanācatl (mushroom) in Náhuatl) and were reportedly served at the coronation of the Aztec ruler Moctezuma II in 1502.
Aztecs and Mazatecs referred to psilocybin mushrooms as genius mushrooms, divinatory mushrooms, and wondrous mushrooms, when translated into English.