Tricholoma highlandense Zhu L Yang, X.X. Ding, G. Kost & Rexer, 2017

Yang, Zhu L., Ding, Xiao-Xia, Kost, G. & K. - H, 2017, New species in the Tricholoma pardinum complex from Eastern Himalaya, Phytotaxa 305 (1), pp. 1-10 : 5-6

1. Tricholoma highlandense Zhu L Yang, X.X. Ding, G. Kost & Rexer , sp. nov. Figs. 2a , 3a–3d

MycoBank MB 819725

Etymology:— highlandense is proposed because of its occurrence on Yunnan Plateau.

Type:— China. Yunnan Province: Ninglang County, Xinyingpan Town, alt. 2500–2600 m, in forest dominated by Pinus yunnanensis , 7 August 2011, Q. Cai 596 (HKAS 70192!).

Description: —Basidiomata medium-sized to large. Pileus 5–10 cm diam, convex to applanate, broadly umbonate; surface dry, white to dirty white to brownish [6A1, 6B2], with brown to dark brown [6C2, 6D 2, 6E 2, 6F2], somewhat reflexed fibrillose squamules; margin incurved or not. Lamellae adnexed to sinuate, white to dirty white to cream-colored [2A2-3], moderately crowded; lamellulae attenuate, arranged in 2–3 tiers, evenly distributed; edges occasionally brownish to yellowish, denticulate. Stipe 3–9 × 1–3 cm, tapering upward, dry, white to dirty white, greyish to yellowish to brownish [4A2-4, 5A2, 5B2, 5C2], covered with brownish fibrillose to reflexed squamules, exannulate, without drops. Context white, solid. Taste and odour indistinct or farinaceous.

Basidiospores [60/3/3] 6.5–8 (–9.5) × 5–6(–6.5) μm [mean length = 7.3 μm, mean width = 5.5 μm, Q = (1.12–) 1.21–1.46(–1.50), Q = 1.33 ± 0.08], broadly ellipsoid to ellipsoid, non-amyloid, colorless, hyaline, thin-walled, smooth; apiculus relatively large. Basidia 37–50 × 8–10 μm, clavate, 4-spored, rarely 2-spored, hyaline; sterigmata 4–5 μm long; basal septa often with clamps. Pleurocystidia absent. Cheilocystidia 40–50 × 8–10 μm, scattered along the lamellar edge, clavate, often mucronate, thin-walled, colorless and hyaline. Lamellar trama regular, composed of colorless, thin-walled hyphae 3–15 μm in diam, branching, sometimes anastomosing; clamps present and common. Subhymenium about 15 μm thick, composed of 2.5–5 μm wide filamentous hyphal segments; clamps common. Pileipellis a cutis with transition to a trichoderm at regular intervals, composed of loosely and more or less radially arranged, 3–8 μm wide, thin-walled, filamentous hyphae, often with fine brownish granular incrustations and yellowish to brownish vacuolar pigments; terminal elements subcylindrical, 30–50 × 3–8 μm, with round apex. Stipitipellis composed of thin-walled, colorless or brownish to yellowish, filamentous hyphae 3–5 μm wide; terminal elements subcylindrical to narrowly clavate, 5–12 μm wide, with round apex. Clamps common in all parts of basidioma.

Habit, habitat, and distribution:—Solitary to scattered on acid red soil in forests dominated by Pinus yunnanensis , and sometimes mixed with fagaceous plants; fruiting in summer in southwestern China in Yunnan Plateau between 2400 and 2800 m altitude .

Additional specimens examined:— CHINA. Yunnan Province: Lanping County, Hexi Town , alt. 2400 m, in forest of Pinus yunnanensis , 16 August 2011, Q. Zhao 1340 ( HKAS 74293 ) ; Lijiang City, Elephant Hill , alt. 2800 m, in forest dominated by Pinus yunnanensis mixed with fagaceous plants, 30 July 2011, T. Guo 258 ( HKAS 71156 ) .

Figures

FIGURE 2. Basidiomes of Tricholoma. a. Tricholoma highlandense (HKAS 70192, type); b. Tricholoma sinopardinum (HKAS 58001). Bars = 2 cm Photos by Q. Cai and Z.L. Yang.

FIGURE 3. Microscopical characters of Tricholoma highlandense (HKAS 70192, type). a. Basidia at different stages of development and subhymenium elements; b. Basidiospores; c. Mucronate or clavate cheilocystidia; d. Pileipellis section. Bars a and c = 20 μm, b = 10 μm, d = 30 μm. Drawings by Zhu L. Yang.