In the Chihuahuan Desert, along the Rio Grande, there is a small blue-green cactus with no spines. It grows so slowly it can take a decade to add half an inch. You could walk past a plant older than you are and not notice it.
Fifteen hundred miles south, on the Andean slopes, a different cactus makes essentially the same compound. That one grows like a weed.
Same chemistry. Opposite fortunes. One is in genuine conservation trouble. The other you can buy in a garden centre.

PeyoteThe slow one
Mescaline was isolated from it by Arthur Heffter in 1897 and synthesized by Ernst Späth in 1919 — which makes it one of the first psychedelics Western science ever pinned down as a single molecule.
Its legal position in the United States is unlike anything else in this book. The Native American Church was formally incorporated in 1918, and federal protection for its sacramental use arrived with the American Indian Religious Freedom Act amendments of 1994. That protection is specific, it is hard-won, and it does not extend to everybody who would like it to.
And here is the ask this book makes.
Peyote grows too slowly to survive being fashionable. Wild populations are declining, the plant does not regenerate on any timescale that suits demand, and the people with the oldest and best-established claim to it are watching that happen.
If the chemistry is what interests you, San Pedro has it and grows fast. That is not a compromise. It is the entire point of this page.
San PedroThe fast one
Echinopsis pachanoi. Columnar, vigorous, and not endangered in any sense. It is depicted at Chavín de Huántar around 1200 BCE, carved into stone by people who had worked out what it did roughly three thousand years before anyone isolated the molecule.

The name is worth a moment. San Pedro — Saint Peter, who holds the keys to the gate. Whoever named it was not being subtle, and they were not being careless either.
Huxley, and a vase of flowers
In 1953 Aldous Huxley took four-tenths of a gram of mescaline and spent a good part of the afternoon looking at a small arrangement of flowers. The Doors of Perception followed in 1954, and a great deal of what came after followed from that.
He was not the first person to find this interesting. He was roughly three thousand years late. He just wrote it down in English.





