San Pedro cactus
The San Pedro Cactus, principle active ingredient is mescaline which can only be used legally by some native American tribes which have a history of using the plant.
The San Pedro cactus is very easy to grow in most areas. Because it grows naturally in the Andes Mountains at high altitude and with high rainfall, it can withstand temperatures far below that of many other cacti. It requires fertile, free-draining soil. They average half a meter per year of new growth. They are susceptible to fungal diseases if over-watered, but are not nearly as sensitive as many other cacti, especially in warm weather. They can be sunburned and display a yellowing chlorotic reaction to overexposure to sunlight.
In winter, plants will etiolate, 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.
More info in the Hallucinogens Brochure