Lophophora williamsii or peyote is a small, spineless cactus with psychoactive alkaloids, particularly mescaline. Peyote is a Spanish word derived from the Nahuatl, or Aztec, peyōtl, meaning “glisten” or “glistening”. Other sources translate the Nahuatl word as “Divine Messenger”. Peyote is native to Mexico and southwestern Texas. It is found primarily in the Chihuahuan Desert and in the states of Coahuila, Nuevo León, Tamaulipas, and San Luis Potosí among scrub. It flowers from March to May, and sometimes as late as September. The flowers are pink, with thigmotactic anthers (like Opuntia).
Known for its psychoactive properties when ingested, peyote is used worldwide, having a long history of ritualistic and medicinal use by indigenous North Americans. Peyote contains the hallucinogen mescaline.
The various species of the genus Lophophora grow low to the ground and they often form groups with numerous, crowded shoots. The blue-green, yellow-green or sometimes reddish-green shoots are mostly flattened spheres with sunken shoot tips. They can reach heights of from 2 to 7 centimeters (0.79 to 2.76 in) and diameters of 4 to 12 cm (1.6 to 4.7 in). There are often significant, vertical ribs consisting of low and rounded or hump-like bumps. From the cusp areoles arises a tuft of soft, yellowish or whitish woolly hairs. Spines are absent. Flowers are pink or white to slightly yellowish, sometimes reddish. They open during the day, are from 1 to 2.4 cm long, and reach a diameter from 1 to 2.2 cm.
The cactus produces flowers sporadically; these are followed by small edible pink fruit. The club-shaped to elongated, fleshy fruits are bare and more or less rosy colored. At maturity, they are brownish-white and dry. The fruits do not burst open on their own and they are between 1.5 and 2 cm long. They contain black, pear-shaped seeds that are 1 to 1.5 mm long and 1 mm wide. The seeds require hot and humid conditions to germinate. Peyote contains a large spectrum of phenethylamine alkaloids. The principal one is mescaline for which the content of Lophophora williamsii is about 0.4% fresh (undried) and 3–6% dried.
Peyote is extremely slow-growing. Cultivated specimens grow considerably faster, sometimes taking less than three years to go from seedling to mature flowering adult. More rapid growth can be achieved by grafting peyote onto mature San Pedro rootstock. The top of the above-ground part of the cactus, the crown, consists of disc-shaped buttons. These are cut above the roots and sometimes dried. When done properly, the top of the root forms a callus and the root does not rot. When poor harvesting techniques are used, however, the entire plant dies. Currently, in South Texas, peyote grows naturally but has been over-harvested, to the point that the state has listed it as an endangered species. The buttons are generally chewed, or boiled in water to produce a psychoactive tea. Peyote is extremely bitter and most people are nauseated before they feel the onset of the psychoactive effects.