Wikipedia:Today's featured article/June 3, 2015

Psilocybe semilanceata is a fungus whose mushrooms, known as liberty caps, are also called magic mushrooms for their psychedelic properties. They are the most common of the psilocybin mushrooms, and among the most potent. They have a distinctive conical or bell-shaped cap, up to 2.5 cm wide, with a small nipple-like protrusion on the top. Yellow to brown in color and fading to a lighter color as they mature, they feed off decaying grass roots in fields, grassy meadows, and similar habitats, particularly in wet fields that are well-fertilized by sheep and cattle manure. The mushroom is widely distributed in the cool temperate and subarctic regions of the Northern Hemisphere, particularly in Europe, and has been reported occasionally in India, South America, and Australasia. The earliest reliable history of P. semilanceata intoxication dates back to 1799 in London. In the 1960s the mushroom was the first European species confirmed to contain psilocybin; it was later found to contain the psychoactive compounds phenylethylamine and baeocystin as well. The possession or sale of psilocybin mushrooms is illegal in many countries.