Psilocybe semilanceata, commonly known as the liberty cap, is a psychedelic (or “magic”) mushroom that contains thepsychoactive compounds psilocybin and baeocystin. Of the world’s psilocybin mushrooms, it is the most common in nature, and one of the most potent. The mushrooms have a distinctive conical to bell-shaped cap, up to 2.5 cm (1.0 in) in diameter, with a small nipple-like protrusion on the top. They are yellow to brown in color, covered with radial grooves when moist, and fade to a lighter color as they mature. Their stems tend to be slender and long, and the same color or slightly lighter than the cap. The gillattachment to the stem is adnexed (narrowly attached), and they are initially cream-colored before tinting purple as the sporesmature. The spores are dark purplish-brown in mass, ellipsoid in shape, and measure 10.5–15 by 6.5–8.5 micrometers.
The mushroom grows in fields, grassy meadows, and similar habitats, particularly in wet, north-facing fields (south-facing for southern hemisphere) that are well-fertilized by sheep and cattle feces. But unlike P. cubensis, the fungus does not grow directly on dung; rather, it is a saprobic species that feeds off decaying grass roots. It is widely distributed in the cool temperate and subarcticregions of the Northern Hemisphere, particularly in Europe. However, it has also been reported occasionally from warmer locations such as India, South America, and Australasia. The earliest reliable history of P. semilanceata intoxication dates back to 1799 in London, and in the 1960s the mushroom was the first European species confirmed to contain psilocybin. Further investigations into the chemical makeup of the fungus revealed the presence of the substances phenylethylamine , and the psychotropic tryptaminebaeocystin .
The toxic species Cortinarius rubellus (formerly known as C. orellanoides) has been confused with P. semilanceata by novice collectors looking to consume the mushrooms for hallucinogenic effects, sometimes with drastic consequences. The expanded and bluntly umbonate cap of C. rubellus is orange-brown with a larger diameter thanP. semilanceata, typically ranging from 2–6 cm (0.8–2.4 in). The gills are adnate to sinuate in attachment to the stem, and cinnamon-brown in color (rather than dark gray to purple-brown). Its stem is roughly the same color as the cap, 5–8 cm (2.0–3.1 in) long and much thicker than P. semilanceata—usually 0.6–1 cm (0.2–0.4 in), and sometimes bears lemon-yellow bands. It is a mycorrhizal species that grows on acidic soil among mosses, usually in wet coniferous forests. P. semilanceata has also been confused with the toxic muscarine-containing species Inocybe geophylla, a whitish mushroom with a silky cap, yellowish-brown to pale grayish gills, and a dull yellowish-brown spore print.
Bad Look Alikes:: Will kill you.
Deadly webcap (Cortinarius rubellus)
Spore color: Rusty brown to orange
Cap: 3–7 cm rusty brown to orange. Often has a steeper and darker colored elevation at the top of the cap, but this varies greatly from specimen to specimen
Gills: Wide gaps between the gills which can be, but are not necessarily, connected to the stem
Location: Rare, but common in temperate parts of northern Europe. Has been encountered as far north as Finnish Lapland.
Habitat: Pine woods with acidic soil
Other details: Young specimens contain a pale web between the cap and the stem. Sometimes parts of this web can be seen as a yellow ring on the stem or at the edge of the cap. The fruiting body of the mushroom blossoms from mid-summer to late autumn.
Fool’s webcap (Cortinarius orellanus)
Spore color: Rusty brown to orange
Cap: 3–8.5 cm, concave
Gills: Similar to those of the deadly webcap
Location: Common throughout Europe, rare in the northern parts of Europe. Has been observed as far north as southern Norway
Habitat: In forests, around trees where the soil is alkaline or acidic
Other details: Young specimens of the Fool’s webcap also contain a web between the cap and the stem that partially or completely disappears as the specimen ages.