Macroscopic feat.:

• Cap/Pileus: Approx. 10 mm in diam and approx. 13 mm high, campanulate subpapillate, sublubricous, even to slightly striate toward the margin, grayish leather to brownish straw-yellow, hygrophanous.
• Gills/Lamellae: Adnate, brownish violet, uniform in colour.
• Stem/Stipe: Approx. 40 x 3 mm, cylindric, sinuous, hollow, whitish to reddish brown, covered by floccose appressed white scales, mainly in the middle part. Both pile us and stipe staining blue to blackish where injured.
• Context: Whitish to concolourous with the pileus.
• Odor: And taste farinaceous.

Microscopic feat.:

• Basidio/Spores: (4-) 4.5-5 (5.5) x 4-5 x 3-4 µm, subrhomboid in face view, subellipsoid in side view, with a thick wall up to 1 µm, brownish yellow, with a broad germ pore at one end and an acute short appendage at the other.
• Basidia: (12-) 14.5-21 x 5-7 µm, 4-spored, clavate ventricose, hyaline.
• Pleurocistidia: 11-14.5 (-16) x (4-) 5-6.5 (-7) µm, common, hyaline, ventricose rostrate, with a short apex.
• Cheilocystidia: Of two types, a) as the pleurocystidia (10.5-) 12-16 (-17.5) x 5.5-6.5 µm, hyaline, and b) (16-) 17-22.5 x 5-8 µm, ventricose, regular or irregularly in form, hyaline.
• Subhymenium: With globose elements 3-5 µm in diam, hyaline or yellowish.
• Trama: Regular, formed by yellowish or hyaline hyphae, 3-12 µm wide, thin or thick-walled (up to 1.5 µm).
• Epicutis: Subgelatinized, formed by repent hyphae 2.5-5.5 µm wide, with some hyaline ascending elements, 12-32 x 6-8 µm.
• Hypodermium: With subglobose elements 4-16 µm in diam, yellowish to yellow-brown, wall up to 1.5 µm thick. Clamp connections present.

Habitat: Solitary on logs, in coffee plantations remainding of subtropical cloud (mesophytic) forests. Known only from the type locality.

Studied material: MEXICO: State of Chiapas, Region of Tapachula, Municipio Union de Juárez, Ejido Santo Domingo, Oct. 4, 1993, Guzmán 30739 (Holotype, XAL).

Discussion: This species is close to Psilocybe yungensis Singer & Smith and Psilocybe subyungensis Guzmán by similar pileus form, spores size and the lignicolous habitat, but differs by more abundant pleurocystidia (scanty in those species) and in their size (14-25 µm long in Psilocybe yungensis; 9-11 µm long in Psilocybe subyungensis, and in the size and variability of the cheilocystidia [14-33 (-40) µm long in Psilocybe yungensis; 16,5-25 µm long in Psilocybe subyungensis].

source - Bibliotheca Mycologica [159: 102-103]

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