Psilocybe mexicana is a psychedelic mushroom. Its first known usage was by the natives of North and Central America over 2,000 years ago. Known to the Aztecs as teotlnanácatl from Nahuatl: teotl “god” + nanácatl “FUNGUS”. This species was categorized by French botanist Roger Heim.

It was from this species that Dr. Albert Hofmann, working with specimens grown in his Sandoz laboratory, first isolated and named the active entheogenic compounds psilocybin and psilocin. Uncertain of whether or not the artificially cultivated mushrooms would retain their natural psychoactive properties, Dr. Hofmann consumed 32 specimens.