Echinopsis pachanoi (syn. Trichocereus pachanoi) — known as San Pedro cactus — is a fast-growing (up to 12 inches or more in a year) columnar cactus native to the Andes Mountains at 6,600–9,800 ft in altitude. It is found in Argentina, Bolivia, Chile, Ecuador and Peru, and it is cultivated in other parts of the world.
Echinopsis pachanoi is known by many names throughout South America such as achuma, huachuma, wachuma, aguacolla, hahuacollay, or giganton. Uses for it include traditional medicine and traditional veterinary medicine, and it is widely grown as an ornamental cactus. It has been used for healing and religious divination in the Andes Mountains region for over 3,000 years.
The name San Pedro (Saint Peter) is attributed to the belief that just as St Peter holds the keys to heaven, the effects of the cactus allow users "to reach heaven while still on earth."
Like Peyote, San Pedro contains mescaline. Traditionally San Pedro may be consumed either on its own or with other plants in a ceremonial brew called "cimora". Many of the artifacts associate the sacred cactus with the jaguar, hummingbird, deer, boa, owl, snail, and stylized spirals or steps — symbols thought to represent aspects of the visionary experience itself.
People with liver problems, colon problems, high blood pressure, heart conditions, diabetes, or mental illness are advised to be cautious. It should also be avoided by pregnant or breastfeeding women.