Trans. Brit. Myc. Soc. 29(3) 141. 1946.
Common Name: none
Cap 2-4.5 cm broad, convex, becoming nearly plane with a low umbo; margin striate, often wavy, sometimes upturned in age; surface smooth, sticky when moist, hygrophanous, brown, fading to yellow-brown or buff; flesh thin, brittle in age, bruising blue.
Gills adnate to seceding, close when young, subdistant in age, pale cinnamon brown, becoming dark grey-brown, edges lighter than the faces, mottled from spores at maturity.
Stipe 3-6 cm tall, 3-6 mm thick, equal to sometimes enlarged at the base, the latter with conspicuous thickened mycelium (rhizomorphs); surface white, smooth to silky, bruising blue; veil fibrillose, forming a superior, evanescent hairy, annular zone.
Spores 9-12 x 6-8 µm, elliptical, smooth, with an apical pore; spore print purple-brown to purple-grey.
Scattered to gregarious on woody debris, leaf litter, and wood chips; fruiting from late summer in watered areas to mid-winter.
Psilocybe cyanescens is recognized by a chestnut-brown, striate, wavy-margined cap that soon fades to yellow brown or buff, and blue-staining fruiting body. Because of its hallucinogenic properties, it is sometimes the subject of experimentation, a potentially dangerous practice because of toxic look-alikes in Galerina, Conocybe and Inocybe.
Bas, C., Kyper, Th. W., Noordeloos, M.E. & Vellinga, E.C. (1999). Flora Agaricina Neerlandica — Critical monographs on the families of agarics and boleti occurring in the Netherlands. Volume 4. Strophariaceae, Tricholomataceae. A. A.Balkema: Rotterdam, Netherlands. 191 p.
Benjamin, D.R. (1995). Mushrooms: Poisons and Panaceas. W. H. Freeman: New York, NY. 422 p.
Dennis, R.W. & Wakefield, E.M. (1946). New or interesting British fungi. Transactions of the British Mycological Society 29(3): 141-166. (Protologue)
Doveri, F. (2004). Fungi Fimicoli Italici. Associazione Micologica Bresadola: Trento, Italy. 1104 p.
Guzmán, Gastón (1983). The Genus Psilocybe. J. Cramer: New York, NY. 439 p. (PDF)
Noordeloos, M.E. (2011). Strophariaceae s.l. Edizioni Candusso: Alassio, Italy. 648 p.
Singer, R. & Smith, A.H. (1958). Mycological Investigations on Teonanácatl, the Mexican Hallucinogenic Mushroom. Part II. A Taxonomic Monograph of Psilocybe, Section Caerulescentes. Mycologia 50: 262-303.
Stamets, P. (1996). Psilocybin Mushrooms of the World. Ten Speed Press: Berkeley, CA. 245 p.
Watling, Roy & Gregory, Norma M. (1987). British Fungus Flora: Agarics and Boleti. Vol 5. Strophariaceae & Coprinaceae p.p.: Hypholoma, Melanotus, Psilocybe, Stropharia, Lacymaria, & Panaeolus. Royal Botanic Garden: Edinburgh, Scotland. 121 p.