Tricholoma sinopardinum 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 : 6-7

2. Tricholoma sinopardinum Zhu L Yang, X.X. Ding, G. Kost & Rexer , sp. nov. Figs. 2b , 4a–4f

MycoBank MB 819726

Etymology:— sinopardinum is proposed because of the Chinese mushroom’s similarity to T. pardinum .

Type:— China. Xizang Autonomous Prefecture (Tibet): Jiangda County, Jiangda Town, alt. 3500 m, in forest dominated by Picea sp. and Populus sp. , 8 August 2013, B. Feng 1427 (HKAS 82533!).

Description:— Basidiomata medium-sized to large. Pileus 5–11 cm diam, conico-convex when young, becoming convex to applanate with age, broadly umbonate; surface dry, white to dirty white to grayish [2A2, 2B2], with brown to dark brown to blackish [6D 3, 6E 3, 6F3], 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 often brownish to yellow-brown, denticulate. Stipe 5–18 × 1–3 cm, clavate to subcylindrical, often tapering upward, dry, white to dirty white, greyish to yellowish to brownish [4A2-4, 5A2, 5B2, 5C2], covered with brownish, brown to dark brown fibrillose to reflexed squamules, exannulate, without drops. Context white solid. Taste and Odour indistinct or farinaceous or fishlike.

Basidiospores [115/6/5] (8–)8.5–10.5(–11.5) × (5.5–)6.5–7.5 (–8) μm [mean length = 9.3 μm, mean width = 6.9 μm, Q = (1.20–)1.25–1.50(–1.62), Q = 1.36 ± 0.09], mostly ellipsoid, sometimes broadly ellipsoid, non-amyloid, colorless, hyaline, thin-walled, smooth; apiculus relatively large. Basidia 45–55(–65) × 9–11(–15) μm, clavate, 4-spored, rarely 2-spored, hyaline; sterigmata 4–5 μm long; basal septa often with clamps. Pleurocystidia absent. Cheilocystidia 40– 75 × 15–25 μm, scattered along the lamellar edge, conspicuous, clavate, thin- to slightly thick-walled (≤ 0.5 μm), colorless and hyaline or sometimes brownish or yellowish vacuolar pigment. Lamellar trama regular, composed of colorless, thin-walled hyphae 3–30 μm in diam, branching, sometimes anastomosing; clamps present and common. Subhymenium 15–20 μm thick, composed of 2.5–4 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, 3–10(15) μm wide, thin-walled, filamentous hyphae, often with fine brownish granular incrustations and yellowish to brownish vacuolar pigments; terminal elements subcylindrical, 40–70 × 3–10 μm, with round apex. Stipitipellis composed of thin-walled, 3–6 μm wide filamentous hyphae often with brown to yellowish brown vacuolar pigments; terminal elements subcylindrical with round apex. Clamps common in all parts of basidioma.

Habit, habitat, and distribution:—Solitary to scattered on calcareous soil in forests dominated by Picea spp ., and sometimes mixed with Betula spp ., Populus spp ., or Quercus spp .; fruiting in summer in southwestern China in alpine areas between 3300 and 4100 m altitude. It may also occur in mixed forests of Tsuga and Abies in Nepal.

Additional specimens examined:— CHINA. Xizang Autonomous Prefecture (Tibet): Jiangda County, Jiangda Town, Baizong Mountain, alt. 4100 m, in forest dominated by Picea spp . and Betula sp. , 4 August 2009, Z. L. Yang 5459 (HKAS 58001); Jiangda County, Tongpu Town, alt. 3300 m, in forest dominated by Picea spp ., 2 August 2004, Z. W. Ge 261 (HKAS 46041); Mangkang County, on the way to Sichuan, in forest dominated by Picea likiangensis , 16 July 2009, B. Feng 470 (HKAS 57199); Xiangcheng County, Reda Town, alt. 3600 m, in forest dominated by Picea spp . and Quercus spp ., 16 July 2004, Z. L. Yang 4143 (HKAS 45529, regarded as T. pardinum in Li et al. 2015).

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 4. Microscopical characters of Tricholoma sinopardinum. a. Basidiospores (HKAS 46041); b. Hymenium, subhymenium and lamellar trama (HKAS 46041); c. Basidiospores (HKAS 82533, type); d. Basidia (HKAS 82533, type); e. Cheilocystidia (HKAS 82533, type); f. Pileipellis section (HKAS 45529). Bars a and c = 10 μm, b, d, and e = 20 μm, f = 30 μm. Drawings by Zhu L. Yang.