Trichocereus macrogonus var. pachanoi (synonyms including Trichocereus pachanoi and Echinopsis pachanoi) is a fast-growing columnar cactus, and is one of a number of kinds of cacti known as San Pedro cactus. It is native to Ecuador, Peru and Colombia, but also found in Argentina, Bolivia, Chile and Venezuela and cultivated in other parts of the world. Uses for it include traditional 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.

Trichocereus macrogonus var. pachanoi stems are green, sometimes blue, with a diameter of 6-15 cm (2.4-5.9 in) and usually 6-8 ribs. They produce up to seven yellow to brown spines, each up to 2 cm (0.8 in) long although typically shorter in cultivated varieties, sometimes being mostly spineless. Trichocereus macrogonus var. pachanoi is normally 3-6 m (10-20 ft) tall and has multiple branches. The tallest recorded specimen was 12.2 metres (40 ft) tall.

White flowers are produced at the end of the stems; they open at night and last for about two days. Large numbers can be produced by well established cacti and may open new flowers over a period of weeks. The flowers are large, around 19-24 cm (7.5-9.4 in) long with a diameter of up to 20 cm (7.9 in) and are highly fragrant.

Trichocereus macrogonus var. pachanoi contains a number of alkaloids (especially cactus alkaloids), including the well-studied chemical mescaline. Mescaline is a psychedelic drug and entheogen.

Trichocereus macrogonus var. pachanoi in USDA hardiness zones 8b to 10. The range of minimum temperatures in which it is known to grow is between -9.4 C and 10 C. It can withstand temperatures far below that of many other cacti. It requires fertile, free-draining soil. Plants can grow up to 30 cm per year.
Trichocereus macrogonus var. pachanoi is easily grown from seed.

Type: Perennial or houseplant

Hardiness zones: 8-10

Location: Sun

Seeds per packet: 5