San Pedro Cactus
Trichocereus macrogonus var. pachanoi
Family: Cactaceae
This plant often seems almost spineless, though there are short spines tucked in its fleshy areoles. This columnar cactus branches at the base, and stems grow close together in tight bundles. Plants approach 10-15’ in cultivation, though a few wild plants grow as tall as 40’! The flowers are significantly large and fragrant. The open at night but remain open during the next day. If pollinated the flowers lead to fruits that are spherical and green on the outside. They usually split open to reveal the white flesh and seeds.
Plant in full to part sun. Water about once or twice a month in summer. In winter you may not need to water this much at all. Container plants will need weekly or bi-weekly water in summer, and maybe lightly once a month in winter if it doesn’t rain. These plants are pretty hardy for a columnar cactus and can tolerate temperatures down to 15°F. You might cover the new growing tips if the temperatures approach the teens °F.
Plants are bat and moth pollinated. The fruit provides food for birds and other animals and insects.
Trichocereus macrogonus var. pachanoi contains a number of alkaloids (especially cactus alkaloids), including the well-studied chemical mescaline. Mescaline is a psychedelic drug which is also found in some species of cacti. It induces a psychedelic state comparable to those produced by LSD and psilocybin, but with unique characteristics. Anecdotal evidence suggests that the highest concentration of active substances is found in the layer of green photosynthetic tissue just beneath the skin. Mescaline is not evenly distributed within single specimens of San Pedro cactus.
The genus, Trichocereus, comes from the Greek word thrix (Trich), which means "hair" or "hairy", and the word Cereus, which means candle or torch, thus “hairy candle”. The specific epithet macrogonus is derived from the Greek words makros for 'large' and gonia for 'edge' and refers to the ribs of the species. The variety, pachanoi, is named for Prof. Abelardo Pachano of the Quinta Normal de Agricultura in Ambato, Ecuador, “who accompanied Dr. Rose in 1918 on his travels in the high Andes of Ecuador” (Britton & Rose), where he collected the species together with J.N. Rose and George Rose. There are 6 species of Trichocereus native to South America.
The nocturnal flowers are extremely fragrant and remain open into the next day. Photo by Annika Lindqvist, iNaturalist
The fruits burst open, seemingly encouraging birds and other animals to help disperse the seed. Photo by MasterTriangle12 on Wikipedia