- Cap/Pileus: 10-55 mm diam., convex, becoming appianate to slightly depressed, with a small acute umbo at the centre, smooth, glabrous, slightly sticky when moist, translucent-striate towards margin, initially brownish grey (5C2), brownish orange (5C3) or greyish brown (5D3), uniformly turning to greyish brown (6E3,
7E3, 7D3) with brownish grey umbo (5F2, 6F2), sometimes greyish yellow (4C3), greyish orange (5B4), brownish orange (5C5), or light brown (5D6) towards centre, pale yellow (4A3) or greyish yellow (4B3) towards margin with olive brownish grey (4F2) umbo, hygrophanous; margin decurved, becoming plane, entire, sometimes
becoming eroded or fissile.
- Context: Context up to 4 mm thick, whitish or concolorous with the pileus surface.
- Gills/Lamellae: Adnexed to sinuate, initially greyish yellow (4B3), orange grey (5B2) or brownish orange (5C3), becoming greyish brown (6D3) to brown (6E4, 7E4), close, up to 7 mm wide; edge pale, entire.
- Stem/Stipe: 20-80 x 2-10 mm, central, terete, hollow, orange white (4A2) or greyish yellow (4B3), smooth, with a superior, membranous, white annulus; base enlarged, with strigose basal mycelium. Stipe and pileus turning blue on bruising or aging.
- Odor: Sharp and unpleasant when mature.
- Basidio/Spores: 8-9.5 (-11) x 6.5-7 (-8) x (5-) 5.5-6 (-6.5) µm, lenticular, subrhomboidal in face-view, ellipsoid in side-view, pale brownish or pale violet-brown, smooth, thick-walled, apically truncated by a germ-pore. Spore-print dark brown (8F4, 8F5).
- Basidia: (21.5-) 26-28 (-34) x 7-9 (-10) µm, subventricose or cylindric to clavate, hyaline, 4-spored; sterigmata up to 4 µm long.
- Pleurocistidia: (16-) 18-30 (-34) x (7-) 9-12 (-14.5) µm, hyaline, thin-walled, subventricose, with an acute apex and narrow base, often with a subgelatinous secretion at the apex.
- Cheilocystidia: (11-) 13-21 (-26.5) x (5-) 6-9 (-12) µm, subventricose, ventricose-fusoid or sublageniform, thin-walled, hyaline, with an acute or obtuse apex, often with a subgelatinous secretion at the apex.
- Trama: Hymenophoral, regular to subregular; hyphae 2-20 µm wide, thin-walled or wall up to 1 µm thick, hyaline to pale brownish. Context in the pileus interwoven, pale brownish, with 2-24 µm wide, hyaline hyphae, thin-walled or wall up to 1.5 µm thick. Context in the stipe composed of 2-22 µm wide, thin-walled. hyaline or faintly bluish hyphae.
- Epicutis: An ixocutis; hyphae 2-12.5 µm wide, thin-walled. with faint hyaline encrustations. Stipitipellis a repent cutis, with 1.5-14.5 µm wide, thin-walled, hyaline or bluish hyphae.
- Caulocystidia: Similar to cheilocystidia in shape, restricted to the extreme tip of the stipe, either in dusters or scattered, often with a subgelatinous secretion at the apex. Clamp-connections present.
On soil rich with wood chips, gregarious to scattered, July-October. Known only from the type locality.Studied material:
India, Kerala State, Wayanad District, Muthanga, 21 July 1999, Thomas T-320a
(holotype, XAL; isotype, L); 25 July 1999, Thomas T-320b
(XAL, L); 27 July 1999, Thomas T-320c
(XAL, L); 31 October 1999, Thomas T-320d
The annulus, the subrhomboid, thick-walled spores, and the bluing reaction place this new species in Sect. Stuntzii
Guzmán (Guzmán, 1983). It is different from Psilocybe stuntzii
Guzmán & Ott from the USA in the presence of pleurocystidia and in the shape of the cheilocystidia. Psilocybe subaeruginascens
Hohnel from Java and southern Japan is a close species, but the spores are (8-) 9-10 (-13) x 7-8 (-8.5) x 5-7 µm and the cheilocystidia are (16-) 18-23 (-33) x (4.5-) 5.5-9 µm (Guzmán, 1983). Psilocybe septentrionalis
(Guzmán) Guzmán (Guzmán, 1995), known only from northern Japan, is also a very close species, but differs in the size and shape of pleurocystidia (14-23 x 9-10 µm) and cheilocystidia (16-25 x 5.5-7.5 µm).source - www.mycotaxon.com [83: 198-202]Pictures at www.mushroomobserver.org