Summary:
Features include 1) a hygrophanous, deep chestnut brown, viscid, peelable cap, 2) flesh that bruises bluish, 3) light grayish gills that become purplish brown with white edges, 4) a yellow brown to light tan stem with fine, light grayish fibrils that become bluish when handled, 5) a farinaceous taste, 6) coastal fruiting with lupines and rhododendrons, 7) a purplish brown spore deposit, and 8) microscopic characters.

Cap:
1.4-3.5cm across, conic to convex to broadly convex, eventually flat when old, typically not umbonate; hygrophanous, deep chestnut brown, fading in drying to pale tan to yellowish brown, even dingy grayish white; viscid when moist from a separable gelatinous pellicle [cap skin], (Stamets), 1.4-3.5cm across, conic to broadly convex, eventually flat when old; "hygrophanous, deep chestnut brown, fading to light tan or light yellowish brown to somewhat whitish"; bald, "viscid when moist from a separable gelatinous pellicle", (Guzman(1))

Flesh:
brownish, bruising bluish, (Stamets), brownish in cap and stem, "middly bluish [sic] when bruised", (Guzman(1))

Gills:
adnate to adnexed to slightly subdecurrent when old, light grayish when young, becoming purplish brown when mature, with edges whitish, (Stamets), adnate or adnexed to short-decurrent, moderately broad; light grayish when young to purplish brown when old, edges pallid, (Guzman(1))

Stem:
3-7cm x 0.2-0.4cm, equal to widened near base, straight to flexuous [wavy]; yellow brown to light tan underneath fibrils; longitudinally striate, and adorned with fine fibrils that become bluish when handled, (Stamets), 3.0-7.0 x 0.2-0.4cm, equal or widening downwards, fibrous, "hollow to stuffed with a yellowish pith", "flexuous or straight, sometimes curved near base", hollow to stuffed with a yellowish pith; "light tan to yellowish brown, covered with fine light grayish fibrils" that soon turn bluish when old or when touched; longitudinally striate, (Guzman(1))

Veil:
partial veil "white, cortinate, copious, leaving fibrillose veil remnants", sometimes a fragile ring zone on the upper part, (Stamets), "copious at first, whitish and cortinate, leaving fibrillose remnants" especially on upper part of stem, but not forming ring, (Guzman(1))

Taste:
more or less farinaceous, (Guzman(1))

Microscopic spores:
spores (9)9.5-11(12) x (5.5)6-6.6(7) microns, subelliptic [somewhat elliptic]; basidia 4-spored, rarely 2-spored; pleurocystidia absent, cheilocystidia fusiform to lanceolate, 22-33 x 5.5-7 microns, with an elongated, forking neck, 1-1.5 microns wide at apex, (Stamets), spores (9)9.5-11(12) x (5.5)6-6.6(7.1) microns, subelliptic in both face and side view, "pale or more or less dark chocolate brown", thick-walled, with distinct germ pore; basidia 4-spored or sometimes 2-spored, 22-28 x 6-9.5 microns, with sterigmata up to 5 microns long, colorless, "ventricose or subpyriform, frequently with a median constriction"; pleurocystidia absent, cheilocystidia abundant, forming a sterile band, 22-33 x 5.5-7 microns, colorless, "fusiform to lanceolate, sometimes subpedicellate", with an elongate neck 1-1.5 microns wide; clamp connections present, but not common, (Guzman(1)), [spores presumably smooth]

Spore deposit:
purplish-brown (Stamets)

Notes:
Psilocybe cyanofibrillosa has been found primarily along coastal regions from northern CA to BC, (Stamets). Collections were studied from WA (Guzman(1)).

EDIBILITY

weakly to mildly active, containing up to 0.21% psilocybin and 0.062% psilocin, but actual potency of fresh specimens "is probably much higher than chemical analyses revealed" because it "loses much of it potency from handing and in drying", (Stamets)

Synonyms and Alternate Names:
Psilocybe rhododendronensis Stamets nom. prov.