Macroscopic feat.:

• Cap/Pileus: 25-65 mm diam., subconvex to subumbonate, smooth to substriate at the margin, some rimose in old specimens, viscid to subviscid, hygrophanous, brown or reddish brown to brownish yellow, some straw-colored.
• Gills/Lamellae: Subadnate or sinuate, yellowish violaceous to brownish violaceous or chocolate brown, somewhat mottled; edges whitish to concolorous.
• Stem/Stipe: 80-95 x 5-9 mm, cylindrical, equal or slightly subbulbous, hollow, whitish to yellowish, finally brown reddish to blackish; staining blue when touched or injured; covered by floccose white fibrils toward the base.
• Context: White and fleshy in the pileus, yellowish and subgelatinous to subcartilaginous in the stipe; staining blue when cut.
• Odor: Farinaceous.

Microscopic feat.:

• Basidio/Spores: (6-) 6.6-7.7 (-8.5) x 5.5-6.6 (-7.1) x 3.5-5.5 µm, subrhomboid, some obscurely angular in face view, but broadly elliptic or subelliptic in side view, smooth, yellowish brown thick walled, with broad flattened germ pore.
• Basidia: 20-30 x 6-8 µm, four spored, vesiculose-pyriform, with a slight constriction in the middle.
• Pleurocistidia: 15-22 x 5.-6.6 µm, hyaline, not abundant, vesiculose-fusoid, attenuate above and with a rounded nucro or sublageniform, neck 3.3-4 µm across.
• Cheilocystidia: 13-22 x 4.5-6 µm, hyaline, ventricose-rostrate, with necks 2-2.5 µm, forming a sterile band along the gill edge.
• Subhymenium: Yellowish with irregular brownish yellow pigment incrustations.
• Trama: Hyaline to yellowish, parallel, colored by brownish yellow pigmented irregularly incrusted hyphae which often resemble collapsed chrysocystidia.
• Epicutis: Formed by subgelatinized parallel hyphae, which are elongated to subglobose, hyaline to brownish.
• Hypodermium: Yellowish or hyaline, with some latiferous hyphae, hyaline or brownish, 5-7 µm broad. Clamp connections present.

Habitat: Gregarious on grassy soil outside of the subtropical forest at 900 m elevation.

Studied material: ARGENTINA, road Tucumán to Tafi del Valle, 3 km W of Station Aforos, Febr. 18, 1971, Guzmán 8683 (holotype BAFC; isotype ENCB).

Discussion: Psilocybe wrightii is close to Psilocybe caerulescens Murr. but the pleurocystidia and the pigmented trama separate it from the latter as well as the thin floccose stipe. The report of Psilocybe caerulescens by Singer and Digilio (1951) from the Rio de los Sosas, which is close to Aforo Station, it is possible a record of Psilocybe wrightii (no material of that species was available to the author in LIL and in BAFC). The species here described, is certainly hallucinogenic because of its bluing, and its taste and flavor. It is named after Dr. J.E. Wright, who helped the author during his collecting trip to Argentina in 1971.

source - www.mycotaxon.com [7 (2): 251-252]

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