Tricholoma tianshanense Z. X. Zhao, J. G

Tricholoma tianshanense Z.X. Zhao, J.G. Song & B. Xu sp. nov.— FIGURES 2, 3 MycoBank: MB842138 Etymology:—Species epithet based on the Tianshan Mountain in Xinjiang, China, where the species was collected. Diagnosis:—Characterized by fairly inconspicuous, cottony-woolly ring, red to brownish-red scales gradually thinning out towards the marginal zone on the pileus, rarely clamped, guttulated basidiospores. Holotype:— CHINA, Xinjiang Province, Hejing county, Dalongchi Park (42°27′34″N, 80°22′51″E), alt. 2650 m, on rich soil with continuous and thick moss cover in a coniferous forest dominated by plants of Picea schrenkiana Fisch. & C.A.Mey., 11 Sept. 2020, Z. X. Zhao & B. Xu, HMUT 1112. GenBank accession numbers:—ITS: OL584020, LSU: OL584019 (not used in the analyses). Description:— Pileus 4–9 cm in diam, at first hemispherical to convex with involute margin, later convex to planodepressus, breaking up into appressed soon in central part, ± confluent fibrilloso-scales, which are red, to brownish red, scales gradually thinning out towards the marginal zone; margin slightly incurved, thin and sharp, sometimes torn. Lamellae emarginate, whitish to cream-colored, somewhat sinuate, rather close to medium spaced. Stipe 50–100 × 20–25 mm, solidus, cylindrical or tapering downwards, with a persistent but fairly inconspicuous, cottony-woolly ring on the upper part of the stipe, whitish and granulose scales above ring, below ring with irregular, light red to dark red fibrilloso-scales. Flesh whitish, solid; Odor very strong, especially when being fresh, like perfume; taste unknown. Basidiospores (4.5–)5.0–5.9(–7) × (4–)4.6–5(˗6) μm [n=50, Q=(1.02–)1.08–1.50(–1.57), Q=1.29 ± 0.12], broadly ellipsoid to ellipsoid, non-amyloid, hyaline, guttulate, thin-walled, smooth. Basidia (29–)30–41(–45) × 5–8 μm, clavate, 4-spored, rarely 2-spored, hyaline, sterigmata up to 4 μm long. Pleurocystidia / cheilocystidia undetermined. Lamellar trama regular, hyaline, parallel, thin-walled hyphae 5–10 µm diam., sometimes branched. Pileipellis cutis, composed of hyaline, cylindrical, thin-walled hyphae 6–17 µm diam., sometimes branched. Stipitipellis formed by cylindrical 5–12 µm wide hyphae. Clamps present but rare. Ecology & Habitat:—Solitary to scattered on soil with thick mosses cover in forests dominated by Picea schrenkiana, fruiting in summer at alt 2650 m. Distribution:—Currently known only Hejing county, Xinjiang Province, China. Additional specimen examined:— CHINA. Xinjiang Province, Hejing (42°27′34″N, 80°22′51″E), alt. 2650 m, on rich soil with continuous and thick moss cover in a coniferous forest dominated by plants of Picea schrenkiana, 11 Sept 2020, Z. X. Zhao & B. X., HMUT 1114. GenBank accession numbers:—ITS: OL584021, LSU: OL584017 (not used in the analyses).
Published as part of Zhao, Zhen-Xi, Song, Jia-Ge, Senanayake, Indunil C., Wu, Dong-Sheng, Wang, Guo-Qing & Xu, Biao, 2022, Tricholoma tianshanense sp. nov., in Tricholoma sect. Caligata from Tianshan Mountains in China evidenced by morphological characters and phylogenetic analyses, pp. 22-30 in Phytotaxa 549 (1) on pages 26-27, DOI: 10.11646/phytotaxa.549.1.2, http://zenodo.org/record/6605290