Summary:
Fieldmarks include 1) a viscid, peelable, caramel-brown cap that fades as it dries, and usually becomes wavy as it expands, 2) blueing of the flesh and stem, 3) a fleeting veil, and 4) dark spores. Other features include 5) adnate, close to subdistant, broad, cinnamon brown gills that become smoky brown from spores and that often have paler edges, 6) a whitish, silky stem, 7) a farinaceous to mild odor, and 8) growth on humus enriched with woody debris, both in gardens (especially with rhododendrons) and forested areas. "P. cyanescens, originally described from England, appears to represent a complex. In fact the presence of pleurocystidia in the North American taxon suggests it may be a separate species, as in Europe P. cyanescens has no pleurocystidia" (Guzman(4), Latin names italicized). Psilocybe cyanescens is a common Psilocybe in the Pacific Northwest.

Cap:
2-4(5)cm across, obtusely conic to conic-convex at first, soon broadly convex, then flat with an undulating or wavy margin; hygrophanous, chestnut brown becoming caramel brown, then fading to dark yellowish brown or ochraceous on drying; smooth, viscid when moist from a sometimes separable, gelatinous cap skin, margin translucent-striate, (Stamets), (1)2-5(7.5)cm across, subconic or convex to bell-shaped, becoming irregularly expanded flat-convex or flat to depressed, sometimes subumbonate; "hygrophanous, orangish brown, brownish red, grayish pinkish brown, or chestnut color, fading to yellowish, straw color, or ochraceous", easily staining blue when touched or injured; viscid, bald, even, but margin slightly striate when moist, (Guzman(1)), 1.5-4(5)cm across, soon convex to broadly convex, then flat or with uplifted, often wavy margin; dark brown or reddish brown becoming caramel brown, then fading as it dries to tan, yellowish brown, or paler, sometimes with blue or blue-green stains, especially near margin; viscid when moist, smooth, (Arora)

Flesh:
nearly colored as cap and bruising bluish, (Stamets), yellowish and pliant or fleshy in cap, whitish to orangish yellow and cartilaginous in stem mainly toward base, easily staining blue when cut, (Guzman(1)), thin; bruising blue or blue-green, (Arora)

Gills:
adnate to subdecurrent, close to subdistant, broad; cinnamon brown becoming deep smoky brown, edges paler, (Stamets), adnate to sinuate, yellowish brown or orangish brown to violaceous brown, sometimes somewhat mottled, with edges colored as faces or nearly whitish, (Guzman(1)), "typically adnate but sometimes seceding, fairly close"; brown or cinnamon brown becoming dark smoky brown or sometimes bluish-stained, edges whitish, (Arora)

Stem:
2-8cm x 0.2-0.5cm, equal or with a widened base, often curved, stiff but not pliant; whitish, but readily bruising bluish; "silky, covered with fine fibrils and often with long whitish rhizomorphs protruding about base of stem", (Stamets), (4)6-9(11)cm x (0.3)0.4-0.6(0.7)cm, equal, cylindric or somewhat bulbous, straight or sometimes irregularly flexuous [wavy], often with base curved, "hard and cartilaginous, solid to hollow"; white to whitish, readily changing to blue when bruised; silky-fibrillose or scabrous toward base, base with conspicuous white rhizomorphs, (Guzman(1)), 3-8cm x 0.2-0.6(0.8)cm, equal or with widened base, sometimes curved; whitish but staining blue to bluish-green when handled or bruised; dry, (Arora)

Veil:
partial veil "copiously cortinate, snow-white, rapidly deteriorating to an obscure annular zone, if at all", (Stamets), cortinate and well-developed, delicate and white when young, "evanescent in the adults or the remnants remains [sic]", fibrillose in upper part of stem, no ring, (Guzman(1)), "fibrillose or cobwebby, copious but disappearing or at most forming a very slight ring or hairy zone on stalk", (Arora)

Odor:
farinaceous especially when young (Guzman(1)), none (Miller), "mild, farinaceous or earthy" (Siegel)

Taste:
farinaceous especially when young (Guzman(1)), bitter or farinaceous (Siegel)

Microscopic spores:
spores 9-12 x 5-9 microns, elongate-elliptic; basidia 4-spored; pleurocystidia not reported by Wakefield, but collections in Pacific Northwest have abundant capitate pleurocystidia 17-33 x 5-8.8 microns, fusoid-ventricose to subpyriform [somewhat pear-shaped], sometimes mucronate [tipped with an abrupt short point], more common near gill edges, cheilocystidia (12)16-27(30) x (5)6.6-8.8 microns, sublageniform [more or less flask-shaped] to fusoid-ventricose, cylindric at base with extended singly or split neck 6 x 1.5-3.5 microns, (Stamets), spores (8.8)11-13.2(15.4) x (6)6.6-7.7(8.5) x 5.5-7 microns, elongate-elliptic in face and side view, thick-walled (0.1-0.5 microns), dark yellowish brown, with distinct broad germ pore; basidia 4-spored, rarely 2-spored, 20-27(36) x 7-8.5(11) microns, colorless, "vesiculose-subpyriform, sometimes with a slight median constriction"; pleurocystidia not so abundant, more frequently near gill edge, 17-33 x 4.9-8.8 microns, "fusoid-ventricose or subpyriform but all the time mucronate, rarely with more or less long neck", cheilocystidia abundant, (12)16-27(30) x (5)6.6-8.8 microns, colorless, "sublageniform to fusoid-ventricose, rarely pedicellate or with a more or less long cylindrical base, with a long neck, bifurcate or simple", up to 6 x 1.5-3.5 microns; clamp connections very common, (Guzman(1)), spores 11-12(16) x (6)6.5-7(8) x (6)6.5-7 microns, elliptic, thick-walled, wall up to 1.5 microns thick; pleurocystidia common, 17-30 x (4)5.5-8(9) microns, "clavate or narrowly subglobose, both with a short cylindrical apex", cheilocystidia 18-29 x 5.5-7 microns, "sublageniform or narrowly utriform, sometimes branched", (Guzman(4) for BC collection), spores 9-12 x 5-9, elliptic, smooth; chrysocystidia absent on gills, (Arora)

Spore deposit:
dark purplish brown (Stamets), dark brown violet or fuscous (Guzman(1)), "purple-brown to purple-gray or purple-black", (Arora)

Notes:
Collections were examined from BC, WA, OR, CA, United Kingdom (Scotland), and the Netherlands, (Guzman).

EDIBILITY

potent hallucinogen, especially raw, only one or two caps needed to alter perception and sensation, (Arora), 0.3-1.7% psilocybin, 0.28-0.51% psilocin, 0.02-0.03% baeocystin, (Stamets)