Psilocybe silvatica, is a psilocybin mushroom of the Agaricales family, in the section Semilanceatae, having psilocybin and psilocin as main active compounds. It is closely related to P. pelliculosa.

Description

• Cap: 0.8- 2(2.5) cm broad. Sharply or obtusely conic, becoming broadly campanulate to broadly conic, often with a papilla. Tawny dark brown when moist, even to striatulate when moist, smooth, hygrophanous, viscid when moist from a thin gelatinous pellicle that is tenacious. Sometimes with a grayish-green tinge along the margin. Fading to pale buff.
• Gills: Adnate to adnexed, close to subdistant, narrow to moderately broad, dull cinnamon brown at first to smoky brown at maturity, edges remaining whitish.
• Spores: Dark purplish brown
• Stipe: 2-8 cm long by 1-3 mm thick, equal to slightly enlarged at the base, tubular, brittle yet somewhat flexuous. Pallid to brownish beneath a silky fibrillose covering. Becoming darker towards the base, partial veil poorly developed, cortinate, soon evanescent, no annulus present in mature specimens. Slightly bluish-green at base.
• Taste: Farinaceous
• Odor: Farinaceous
• Microscopic features: Spores (6.6)8.5-9.5(11) by (3.8)4-5.5(6) microns from 4-spored basidia; sometimes 2-spored. Pleurocystidia absent. Cheilocystidia 24-34(40) by 4.4-6.6(8.8) microns, fusoid ventricose to lageniform, with a long flexuous neck, 1.6-2.2 microns thick.

Habitat and formation

Gregarious but not cespitose on wood debris or on wood chips or in well decayed conifer substratum or among fallen leaves of hardwoods from the end of September until December. Known from Ontario, the Pacific Northwest, Michigan, New York and northern Europe. The Northwest and European finds are more recent, it was once only known in the northeast.