Name: Psilocybe weilii
Author: Guzmán, Stamets & F. Tapia
Citation: in Guzmán, Tapia & Stamets, Mycotaxon 65: 193 (1997)
Preferred Synonyms:Psilocybe caerulescens Murrill
Deprecated Synonyms: Psilocybe villarrealiae Guzmán, Psilocybe caerulescens var. ombrophila (R. Heim) Guzmán, Psilocybe mixaeensis R. Heim, Psilocybe caerulescens var. mazatecorum R. Heim, Psilocybe mazatecorum R. Heim, Psilocybe caerulescens var. nigripes R. Heim, Psilocybe bispora Guzmán, Franco-Mol. & Ram.-Guill., Psilocybe caribaea Guzmán, T.J. Baroni & Tapia, Psilocybe heliconiae Guzmán, Saldarr., Pineda, G. García & L.-F. Velázquez, Psilocybe wrightii Guzmán, Psilocybe ombrophila, Psilocybe subannulata E. Horak & Guzmán, Psilocybe caerulescens var. weilii
Cap: (2)3 — 6(8.5) cm in diameter, obtusely conic to convex to campanulate, margin incurved or inrolled when young, becoming irregularly lobulated then straight with age, subumbunate, hygrophanous, glabrous, subviscid when moist from separable gelatinous pellicle, translucent-striate at the margin, purple brown or chestnut brown to dark brown, fading to buff or straw yellow as it dries, with the center remaining blackish brown. Often with white scale like remnants along the margin, flesh white, strongly bruising blue with some specimens becoming completely bluish black.
Gills: Subadnate to sinuate, close, cream to light brown or brownish yellow, becoming purple brown as the spores mature, edges subfloccose and remaining whitish.
Spores: Dark violet brown, subrhomboid to subellipsoid, (5.5)6 — 7(7.5) x 5 — 6(6.5) µm, thick walled with broad germ pore.
Stipe: (2.5)4 — 7 cm long (4)5 — 10 mm thick. Equal, slightly subulbous, hollow, whitish to yellowish becoming bluish black and drying to grayish straw with vinaceous tones, whitish subfloccose patches near the base and pruinose or smooth towards the upper region, veil well formed, sometimes leaving a partial annular zone, bruising bluish to blackish when injured, sometimes with the entire stipe completely blue or with vinaceous tones.
Odor: Farinaceous, similar to a cucumber.
Microscopic features: Pleurocystidia subfusoid to sublageniform, 16 — 22 × 5 — 10 µm. Cheilocystidia long necked, lageniform, sometimes forked, 20 — 38 × 5 — 7 µm.