Trichocereus macrogonussubsp. sanpedroM.H.J.van der Meer
Trichocereus pachanoiBritton & Rose
Trichocereus santaensisRauh & Backeb.
Trichocereus schoeniiRauh & Backeb.
Trichocereus torataensisF.Ritter
Echinopsis pachanoi,synonyms includingTrichocereus pachanoi andTrichocereus macrogonus var.pachanoi, is a fast-growing columnarcactus found in theAndes at 2,000–3,000 m (6,600–9,800 ft) in altitude.[3][4] It is one of a number of kinds of cacti known as San Pedro cactus. It is native toEcuador, andPeru, but is also found in Bolivia, Colombia, central Chile, the Canary Islands, and mainland Spain,[2] and is cultivated in other parts of the world.[5][6] 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.[7]
Echinopsis pachanoi has light to dark green stems, sometimesglaucous, with a diameter of 6–15 cm (2.4–5.9 in) and usually 6–8 ribs. The whitishareoles may 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.[4] The areoles are spaced evenly along the ribs, approximately 2 cm (0.8 in) apart.[5]E. pachanoi is normally 3–6 m (10–20 ft) tall and has multiple branches, usually extending from the base but will emerge around broken branches.[4] The tallest recorded specimen was 12.2 metres (40 ft) tall.[5] 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. There are black hairs along the length of the thick base leading to the flower. Oblong dark green fruits are produced after fertilization, about 3 cm (1.2 in) across and 5–6 cm (2.0–2.4 in) long,[4] eventually bursting open to reveal a white flesh filled with small seeds.
Echinopsis pachanoi was first described as the speciesTrichocereus pachanoi by Britton and Rose in 1920. It was reduced to the variety ofT. macrogonus var.pachanoi in 2012.[2] It was said to be distinguished fromT. macrogonus var.macrogonus by the smaller number of spines per areole, and by usually being somewhat shorter with more slender stems.[8] As of November 2025[update],Plants of the World Online regardedTrichocereus as a synonym ofEchinopsis,[9] and reinstated the original nameEchinopsis pachanoi.[2]
Hordenine, an alkaloid found inEchinopsis pachanoiEchinopsis pachanoi, San Pedro Cactus, the tall cactus in the mid-foreground, in its natural habitat in Peru. Several fruits with shrivelled flowers can be seen.
Echinopsis pachanoi is known by many names throughoutSouth America such asachuma,huachuma,wachuma,aguacolla,hahuacollay,lapituq,tsuná,San Pedro orgiganton.[10][11] It has a long history of being used in Andeantraditional medicine.
Archaeological studies have found evidence of use going back two thousand years, toMoche culture,[12]Nazca culture,[13] andChavín culture. AlthoughRoman Catholic church authorities[who?] after the Spanish conquest attempted to suppress its use,[14] this failed, as shown by the Christian element in the common name "San Pedro cactus" –Saint Peter cactus. The name is attributed[by whom?] 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."[15]
In Peruvianshamanism, calledmesa norteña, healers (curanderos) boil the San Pedro cactus, with spines removed, into a bitter drink called cimora, often mixed with tobacco to enhance spiritual visions.[16][17] This brew helps shamans gain "vista" (magical vision) to diagnose illnesses, cleanse spirits, and connect with ancestors or nature spirits at sacred sites like the Las Huaringas lagoons.[16][18] The practice also exists inEcuador,Bolivia, and parts ofChile andArgentina, where indigenous groups like the yachakkuna use San Pedro for healing and spiritual guidance.[19][20]
The early 2000s saw the first major international coverage of traditional plant medicine in publications such asThe New York Times Magazine andNational Geographic Adventure, which featured the Blue Morpho retreat center.[21][22]
In 2022, the Peruvian Ministry of Culture declared the traditional use of San Pedro cactus in northern Peru ascultural heritage.[23]
Mescaline is apsychedelic drug andentheogen, which is also found in some other species of the genusEchinopsis (e.g.Echinopsis lageniformis andEchinopsis tacaquirensis) and the speciesLophophora williamsii (peyote).[26] Mescaline induces apsychedelic state comparable to those produced byLSD andpsilocybin, but with unique characteristics.[27] According to a research project in the Netherlands, ceremonial San Pedro use seems to be characterized by relatively strong spiritual experiences, and low incidence of challenging experiences.[28]
Anecdotal evidence suggests that the highest concentration of active substances is found in the layer of greenphotosynthetic tissue just beneath the skin.[5][29][30][31] Mescaline is not evenly distributed within single specimens of San Pedro cactus.[32]
A small newly plantedEchinopsis pachanoi (San Pedro Cactus) cutting
Echinopsis pachanoi is hardy in USDAhardiness zones 8b to 10.[33] The range of minimum temperatures in which it is known to grow is between -9.4 °C and 10 °C.[34] Because it grows naturally in theAndes at high altitude and with high rainfall, it can for a day or two withstand temperatures far below that of many other cacti if they are dry. It requires fertile, free-draining soil. A good soil mix includes an inorganic lightweight substrate such aspumice orperlite. Plants grow up to 30 cm per year.[5][unreliable source?][35][36] They are susceptible to fungal diseases if over-watered, but are not nearly as sensitive as many other cacti, especially in warm weather when they are in their growth phase. They can be sunburned and display a yellowing chlorotic reaction to overexposure to sunlight.[citation needed][36]
In winter, plants willetiolate, or become thin, due to lower levels of light. This may be problematic if the etiolated zone is not sufficiently strong to support future growth as the cactus may break in strong winds.[citation needed]
InOaxaca, Mexico, they are commonly planted close together to make an impenetrablecactus fence.[37]
Like many other plants,Echinopsis pachanoi can be propagated from cuttings. The result is agenetic clone of the parent plant.[38] It is therefore a popular method of propagating highly prized cultivars, sometimes bygrafting small cuttings onto fast-growing cultivars like the Predominant Cultivar (PC). Some names of cultivars that are highly prized by cactus collectors are Ogunbodede, Vilcabamba A, and Yowie.[39]
A cactus column can be also laid on its side on the ground (like a log), and eventually roots will sprout from it and grow into the ground. After time, sprouts will form and cactus columns will grow upward out of it along its length.[38]
Like a lot of its relatives,Echinopsis pachanoi is easily grown from seed, often by means of a so-called "Takeaway Tek".[40][41][42] This term refers to the practice of sowing cactus seed into plastic containers, such as those many food takeaways are delivered in. This creates a semi-controlled humidity environment chamber for six months to a year, in which the seed may germinate and then grow relatively unbothered by environmental contamination.[43] To accelerate the growth ofseedlings, they can be grafted onPereskiopsis.[44][45]
In most countries, it is legal to cultivateEchinopsis pachanoi. In countries where possession of mescaline and related compounds is illegal and highly penalized, cultivation for the purposes of consumption is most likely illegal and also highly penalized. This is the case in the United States, Australia, Canada, Sweden, Germany, and New Zealand, where it is currently legal to cultivate the San Pedro cactus for gardening and ornamental purposes, but not for consumption.[citation needed]
^Rätsch, Christian (2002).Enzyklopädie der psychoaktiven Pflanzen. Botanik, Ethnopharmakologie und Anwendungen. Aarau: AT-Verlag. p. 15.ISBN978-3-85502-570-1.
^Anderson, Edward F. (2001).The Cactus Family. Pentland, Oregon: Timber Press.ISBN978-0-88192-498-5. pp. 45–49.
^abSharon, Douglas (1978).Wizard of the Four Winds: A Shaman's Story. Free Press.ISBN978-0-02-928580-0.
^Glass-Coffin, Bonnie (2010). "Shamanism and San Pedro through Time: Some Notes on the Archaeology, History, and Continued Use of an Entheogen in Northern Peru".Anthropology of Consciousness.21 (1):44–61.doi:10.1111/j.1556-3537.2010.01021.x.
^Glass-Coffin, Bonnie (2010). "Shamanism and San Pedro through Time: Some Notes on the Archaeology, History, and Continued Use of an Entheogen in Northern Peru".Anthropology of Consciousness.21 (1):44–61.doi:10.1111/j.1556-3537.2010.01021.x.
^Rätsch, Christian (2005).The Encyclopedia of Psychoactive Plants: Ethnopharmacology and Its Applications. Park Street Press. pp. 712–715.ISBN978-0-89281-978-2.
^Worcester, Sharon (2004-09-12)."The Vision Seekers".The New York Times. Retrieved2025-10-26.
^Narby, Jeremy (2006-03-01)."Peru: Hell and Back".National Geographic Adventure. Archived fromthe original on 9 July 2008. Retrieved2025-10-26.
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