Though these common little brown mushrooms may look innocent, P. semilanceata, or “liberty caps,” are among the most potent psilocybin mushroom species worldwide.
In this guide, we’ll uncover the rich and mysterious history of liberty caps, discuss their effects, safety, and legality and provide guidance to foraging your own.
History of the “Liberty Caps” Name
Though commonly known as liberty caps, the official name is Psilocybe semilanceata (Fr.) P.Kumm. (1871), or P. semilanceata for short.
(Fr) is for Fries, referring to Elias Magnus Fries, a Swedish mycologist who wrote the first P. semilanceata mycology description in 1838. P.Kumm is for German scientist Paul Krummer, who re-classified P. semilanceata from the Agaricus to the Psilocybe genus in 1871.
Though officially recognized by mycologists in the late 1800s, the name “liberty caps” was described years earlier in British romantic literature.
In 1808, the poet James Woodhouse described dome-shaped mushrooms thought to be P. semilanceata in his poem “Autumn and the Redbreast, An Ode,” published in his Norbury Park collection. In the poem, Woodhouse likened the mushrooms to a “freedom’s cap.” These were hats initially worn by formerly enslaved people during the Roman Empire and adopted by fighters in the French and American revolutions as symbols of liberty and freedom.
The poem goes as follows:
Like fair umbrellas, furl’d, or spread, Display their many-colour’d head;
Grey, purple, yellow, white, or brown, Shap’d like War’s shield, or Prelate’s crown—
Like freedom’s cap, or Friar’s cowl
Liberty cap mushrooms are also referenced in Omniana – a collection of written messages between poets Robert Southey and Samuel Taylor Coleridge in 1812. They write:
There is a common fungus, which so exactly represents the pole and cap of liberty, that it seems offered by nature herself as the appropriate emblem of Gallic republicanism, — mushroom patriots, with a mushroom cap of liberty.
As well as liberty caps, other nicknames for P. semilanceata have included blue legs, pixie caps, and witches’ hats. Some online sources state that Panaeolus semilanceata is also a synonym for P. semilanceata. However, the Panaeolus genus of fungi would technically categorize Panaeolus semilanceata as a separate species.
