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Liberty capPsilocybe semilanceata

Psilocybe semilanceata is a psychoactive mushroom of European origin that contains psilocybin. It grows in cool, damp grasslands. Identification and poisoning risks are central topics when learning about this species.^[3][4][8]

Psychoactive: controlled substance in Mexico. For information only. Never eat a wild mushroom identified only from photos.

Season in Mexico
HabitatCool, damp grasslands
FamilyHymenogastraceae

How do you identify liberty cap?

liberty cap (Psilocybe semilanceata), features to identify it — Photo: Alan Rockefeller, CC BY 4.0, iNaturalist (cropped) · British Columbia, CA

Cap: Conical to bell-shaped, with a central point. Diameter 0.5–2.5 cm; the review gives this measurement as 5–25 mm.^[2][5]
Color and surface: Light to dark chestnut brown and radially lined when wet; light yellow-brown when dry.^[2]
Gills: Pale at first, becoming purple-black at maturity. They attach narrowly to the stem.^[2]
Stem: Slender, yellowish-brown, 4.5–14 cm long and 1–3.5 mm thick.^[5]
Blue bruising: It can develop blue discoloration after damage. The reaction is often faint in this species.^[3]

What happens if someone eats liberty cap?

It is classified as a controlled psychoactive mushroom and excluded from culinary use. Ingestion can cause poisoning and psychological crises.^[8][15]

Where and when does liberty cap grow?

It inhabits damp meadows and grasslands. It is saprobic, obtaining nutrients from decaying grass roots.^[2][3]

The consulted sources do not establish a Mexican fruiting season. Norwegian records describe fruiting from mid-August to mid-October.^[20]

It is of European origin. Its range includes cool temperate regions of Europe and North America. This page has no verified Mexican records.^[2]

See the mushroom map

History and traditional uses

Ceremonial use of Psilocybe mushrooms in Mexico is documented among Mazatec, Zapotec and Nahua communities. These rituals serve divinatory purposes and traditional responses to illness. María Sabina was a Mazatec healer associated with the veladas of Huautla de Jiménez. R. Gordon Wasson publicized his ceremonial experience in the Life article “Seeking the Magic Mushroom,” published in 1957. Albert Hofmann and his team isolated and identified psilocybin and psilocin from P. mexicana and published their results in 1958. Gastón Guzmán developed the taxonomic revision of the genus in The Genus Psilocybe, published in 1983. This context concerns the history of the genus and Mexican ceremonial species; P. semilanceata is of European origin.^{[4][12][13][14][22]}

Is it legal in Mexico?

Mexico’s Ley General de Salud includes psilocybin, hallucinogenic mushrooms and psilocin in Article 245, section I. Article 248 prohibits the acts described in Article 247 concerning those substances; Article 249 provides for authorization for scientific research. The 1971 UN Convention on Psychotropic Substances places psilocybin and psilocin in Schedule I.^[15][16]

About the name

Psilocybe semilanceata is the conserved type species of Psilocybe following the separation of species into Deconica.^[2]

Fun facts

The English name liberty cap refers to the cap’s resemblance to the Phrygian cap, a symbol of liberty.^[4]
A family poisoning in London, recorded in 1799, forms part of this species’ documented history.^[4]

Frequently asked questions

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Sources

Written with AI help from the cited sources. A second model checked every fact against those sources and removed what they did not support. Updated October 5, 2026