Psilocybe keralensis K.A. Thomas, Manim. & Guzmán, Mycotaxon, 2002

Ma, Tao, Ling, Xiao-Fei & Hyde, Kevin D., 2016, Species of Psilocybe (Hymenogastraceae) from Yunnan, southwest China, Phytotaxa 284 (3), pp. 181-193 : 187-189

Psilocybe keralensis K.A. Thomas, Manim. & Guzmán, Mycotaxon 83: 196, 2002 ( Figs. 2 , 4 )

Pileus 15–20 mm diameter, hemisphearic, subconic or campanulate, not umbonate or papillate, hygrophanous, brown (6C4 or 4B8) to orange brown (5B6-5C8), fading to pale earth yellow (5A4) to straw yellow, surface glabrous, lucidus when dry and often somewhat bluish when touched or on drying, especially at the edge, not viscid and the margin finely translucent striate when moist; context cream white or yellowish white (2A3), bruising ink blue. Lamellae adnate to slightly sinuate, close, beige (5A4) to orange-yellow (5A6) to greyish purple (9C2) or purple-brown (6C2 to 9E5), often with ink blue tinge, edges serrulate and remaining whitish. Stipe 45–75 × 2–4 mm, equal, sometimes flattened and becoming tapered toward the base, nearly concolorous with the pileus, darker below, often with ink blue to blackish tinge when touched or when dry, and shiny when dry; surface longitudinally striate and covered with appressed whitish fibrils or flocculose, sometimes uneven and with scrobicula and grooves; base with white mycelium and often radicating; annulus absent; context fragile, yellowish and yellowish brown towards the surface and base, staining somewhat ink blue when bruised. Odour null or with fresh grassy or slightly mushroomy smell.

Pileipellis an ixocutis, 15–80 μm thick, made up of creeping, interwoven, 2–6 μm wide filiform to slender tubular hyphae, hyaline and colourless, wall-smoothed and thin; subpileipellis more pigmented to dark yellow in KOH. Subhymenium subcellular, hyaline, composed of irregular vesiculose to polygonal or subglobose cells. Hymenium contained rich granular and extracellular dark blue pigment.Hymenophoral trama regular, with filamentous to cylindrical smooth hyphae 2–18 μm diameter, hyaline, colourless to dark yellowish, thin-walled to slightly thick-walled (≤1 μm). Basidia 18.5–28.5 × 5.5–8 μm, hyaline and colourless, long subcylindric to clavate, often constricted in middle and narrowed in lower half, 4-spored and 2-spored, rarely 1-spored; sterigmata (1.5–) 3–5 (–6) μm. Basidiospores (136/6/4) 6–9 (–10, –12) ×5–6.5(–7.5) × 4–6 μm, often subrhomboid or ovoid, sometimes ellipsoid, occasionally inconspicuous subhexagonal in face view, Q = 1.1–1.6 (–1.7, –1.9), Q = 1.35±0.13, ellipsoid or subovoid, sometimes nearly oblong in side view, Q = (1.2–) 1.3–1.8, Q = 1.55±0.15; yellowish brown with purple tinge in water, dark yellow to yellowish brown in KOH, dark purplish brown in deposit; wall smooth, slightly thick (0.5–1 μm), complex, with 0.8–1.5 μm wide apical germ pore. Cheilocystidia abundant, 14–27 (–34.5) × 4–8 μm, hyaline and colourless, ventricose to sublageniform, sometime fusoid or clavate, occasionally nearly cylindric-clavate or obclavate, irregularly branched or not branched, mostly with a 1.5–9.5 (–13.5) × 1–3 μm rostrum or neck, sometimes with an acuminate apex, the top or apex often seems wall thickened or contain some matter. Pleurocystidia relatively rare and scattered, 13–22 × 4–6.5 μm, hyaline, similar to cheilocystidia, but smaller, often with a 1–7.5×1–2 μm neck or rostrum, not branched, the top or apex often seems wall thickened or contain some matter. Caulocystidia abundant, (14.5–) 21–45.5 (–49) × 3.5–8 (–11) μm, scattered, gregarious to clustered at the upper part of the stipe, hyaline, similar to cheilocystidia, but more variable in size, and the neck occasionally with a septum, the top or apex often with a thickened wall or containing some matter. Clamp connections common in all parts of the basidioma.

Distribution: — India ( Thomas et al. 2002) and Southwestern China (Chuxiong, Shangri-La and Zhaotong, Yunnan Province) (new record to China).

Habitat: — Growing solitary to scattered on dung or soil of meadows, or grassland in open area of the forest where cattle have grazed in summer, at 2400–3400m altitude.

Material examined:— CHINA, Yunnan Province: Diqing Tibetan Autonomous Prefecture, Shangri-La County, Namucuo Ecological Park , on dung in grassland, E99°50′32.9, N27°47′30.2ʺ, 3379m, 8 August 2009, Tao Ma, Hui Yang ZD 040 ( IFRD414213 ) ; Chuxiong, Zixi Mountain , on soil of grassland in forest, E101°24′06.7ʺ, N25°01′03.7ʺ, 2465m, 4 August 2010, Tao Ma, Xiao-Fei Ling CX 063 ( IFRD414040 ) ; Zhaotong, Zhaoyang district, Dashanbao , on soil of grassland, E103°22′33.4ʺ, N27°27′01.1ʺ, 2909m, 3 August 2011, Tao Ma, Xiao-Fei Lin g ZY039 ( IFRD415173 ), ZY040 ( IFRD415174 ) .

Note: — Psilocybe keralensis was found on grassland or dung in subtropical to high temperate mountains at an altitude of 2400–3400 m in Yunnan Province. It is characterized by bluing of the basidiomata and hymenium, the subrhomboid or ovoid basidiospores in face view, with medium size 6–9 (–10) × 5–6.5 (–7.5) × 4–6 μm, and often has pseudorhiza at the stem base.

Psilocybe keralensis belongs to the Psilocybe fagicola -complex in Sect. Cordispora Guzmán because of its subrhomboid on face-view and relatively small to medium spores, the characteristic bluing reaction, and the presence of pseudorhiza ( Guzmán et al. 2005). It is closely related to P. columbiana Guzmán of this complex, because of the similar basidiomata and basidiospores. The latter species also grows in meadows in high mountains (altitude 3300–3500m). Psilocybe columbiana differs significantly in its absence of pleurocystidia, as well as having relatively slender cheilocystidia (22–30 × 3.3–6.5 μm) and slightly stout spores [(6.6–) 7.1–8 (–8.8) × (4.9–) 6–6.6 (–7.1) × 4.4–5.5 μm] ( Guzmán 1978, 1983). Psilocybe keralensis is only known from Kerala, India ( Thomas et al. 2002). The Yunnan material shows some variation compared with the India material, such as the pileus without umbo or papilla, and somewhat diversity in colour of the pileus, gills and stems of basidiomata.

Phylogenetically, P. keralensis does not group with species of Sect. Cordispora Guzmán, but nested within the “Zapotecorum ”clade (Ramírez-Cruz et al. 2013), together with P. antioquiensis , P. argentipes , P. thaizapoteca , P. zapotecoantillarum , P. zapotecorum and Psilocybe sp. 1 . In this clade, most members have pseudorhiza and pleurocystidia. Pseudorhiza were not mentioned in the original description of P. zapotecoantillarum Guzmán, T.J. Baroni & Lodge and were not recorded in Psilocybe sp. 1 in the field (Guzmán et al. 2003).

In Guzmán’s sense, P. antioquiensis Guzmán, Saldarr., Pineda, G. García & L.-F. Velázquez belongs to sect. Mexicana as it has relatively larger subrhomboid thick-walled basidiospores compared with that of sect. Cordispora, while the latter four species including Psilocybe sp. 1 belong to sect. Zaptecorum Guzmán due to their subellipsoid, thin-walled basidiospores. Morphologically, P. antioquensis is quite similar to P. keralensis , but P. antioquiensis differs significantly in having relatively slender basidiomata and larger basidiospores [(6–) 8–10 (–11) × (5–)6–6.5 (–7) × 5–6 μm] ( Guzmán 1994, Guzmán et al. 2006). Guzmán et al. (2013) considered P. argentipes , P. thaizapoteca as synonyms of P. subcaerulipes , which are closely related to P. keralensis in their similar basidiomata, as well as most microscopic features. The relatively larger basidiomata, smaller 4-spored basidia (16–25 × 5–6 μm), smaller subellipsoid spores [(5–) 6–7 (–8) × (3–) 4–4.5 × (3–) 3.5–4 μm] and gregarious or caespitose habitat can differentiate P. subcaerulipes from P. keralensis . Psilocybe keralensis is obviously different with P. zapotecorum R. Heim and P. zapotecoantillarum in both macro- and microscopic features ( Guzmán 1983, Guzmán et al. 2003).

Figures

FIGURE 2. Basidiomata of Psilocybe species. A–G: Psilocybe keralensis, A, E: IFRD415173, B: IFRD415174, C–D: IFRD414040, F–G: IFRD414213; H, L: Psilocybe aff. fasciata, IFRD415224; I–K, M–N: Psilocybe ruiliensis, I–J: IFRD415243, K, N: holotype, IFRD415241, M: IFRD415240.

FIGURE 4. Psilocybe keralensis (IFRD415173), A: Basidia, B: Basidiospores, C: Cheilocystidia, D: Pleurocystidia, E: Caulocystidia. Scal bar=10 μm.