Echinopsis pachanoi, commonly known as the San Pedro cactus, is a fast-growing cactus native to the Andes mountains in South America. It features tall, columnar stems that can reach heights of up to 20 feet and is characterized by its ribbed surface and spines. The cactus blooms beautiful white or yellow flowers, typically opening at night. This species is known for its psychoactive properties due to the presence of mescaline, a naturally occurring hallucinogen. Traditionally, Echinopsis pachanoi has been used in indigenous rituals for spiritual and healing purposes. It is also cultivated as an ornamental plant in gardens and homes.