Mexicana

As with many of the Psilocybe species known today, Psilocybe mexicana grows natively in areas of North and Central America, where it has been used in indigenous cultural practices for over 2,000 years.
Valentina Pavlovna Wasson and her husband Roger Gordon Wasson collected Psilocybe mexicana during a two-year journey around Mexico (1953-1955), which included a visit to Maria Sabina, the well-known Mazatec curandera credited with introducing psilocybin mushrooms to the world. (R. Gordon Wasson detailed his experience participating in a magic mushroom ceremony led by Sabina in a 1957 photo essay for Life magazine.)

The French botanist Roger Heim, who was sent samples of the mushroom by the Wassons, categorized the species in 1957. Then, in 1958, Albert Hofmann (the Swiss chemist who first syntheized LSD) isolated psilocybin and smaller amounts of psilocin from Psilocybe mexicana. And it was he who gave these psychedelic compounds the names psilocybin and psilocin.

Unsure about whether artificially grown mushrooms would retain their psychoactive properties, Hofmann consumed 32 specimens of Psilocybe mexicana. He recounted the experience in the book The Botany and Chemistry of Hallucinogens (1973), co-authored with the ethnobotanist Richard Evans Schultes. Here are some descriptions from that account:

“As I was perfectly aware that my knowledge of the Mexican origin of the mushrooms would lead me to imagine only Mexican scenery, I tried deliberately to look on my environment as I knew it normally. But all voluntary efforts to look at things in their customary forms and colours proved ineffective. Whether my eyes were closed or open, I saw only Mexican motifs and colours. When the doctor supervising the experiment bent over me to check my blood pressure, he was transformed into an Aztec priest…At the peak of the intoxication…the rush of interior pictures, mostly changing in shape and colour, reached such an alarming degree that I feared I would be torn into this whirlpool of form and colour and would dissolve.”