Three new species of Tricholomopsis (incertae sedis) from North China based on morphological and molecular data Author Mao, Ning 0000-0003-1564-9446 College of Life Sciences, Capital Normal University, Xisanhuanbeilu 105, Haidian, Beijing 100048, China & 373898825 @ qq. com; https: // orcid. org / 0000 - 0003 - 1564 - 9446 373898825@qq.com Author Xu, Yu-Yan 0000-0003-2501-5607 College of Life Sciences, Capital Normal University, Xisanhuanbeilu 105, Haidian, Beijing 100048, China & 1335805640 @ qq. com; https: // orcid. org / 0000 - 0003 - 2501 - 5607 1335805640@qq.com Author Fan, Li 0000-0001-9887-7086 College of Life Sciences, Capital Normal University, Xisanhuanbeilu 105, Haidian, Beijing 100048, China & fanli @ mail. cnu. edu. cn; https: // orcid. org / 0000 - 0001 - 9887 - 7086 fanli@mail.cnu.edu.cn text Phytotaxa 2021 2021-06-09 507 2 155 166 http://dx.doi.org/10.11646/phytotaxa.507.2.3 journal article 10.11646/phytotaxa.507.2.3 1179-3163 5425603 Tricholomopsis mitirubicunda L. Fan & N. Mao , sp. nov. ( Figs. 2 , 3 ) MycoBank :—MB839213 Diagnosis:— Pileus 60–80 mm diam, yellow-brown to red-brown, covered with yellow-brown to red-brown fibrillose scales, lamellae crowded, free, white to pale yellowish, basidiospores ellipsoid, Q = (1.33–) 1.42–1.67 (–1.75), cheilocystidia narrowly clavate to sphaeropedunculate, pleurocystidia abundant. FIGURE 3. Microscopic features. Tricholomopsis galeata (BJTC FM1107, holotype) a . Basidiospores b . Cheilocystidia c . Pileipellis elements; Tricholomopsis pallidolutea (BJTC FM1184, holotype) d . Cheilocystidia e . Basidiospores f . Pleurocystidia g . Pileipellis elements; Tricholomopsis mitirubicunda (BJTC FM649, holotype) h . Cheilocystidia i . Basidiospores j . Pleurocystidia k . Pileipellis elements. Scale bars: h = 20 μm; a , b , c , d , f , g , i , j , k = 10 μm; e = 5 μm. Drawings by: Ning Mao. Etymology : — ‘ mitirubicunda ’, refers to the soft pink color of the pileus margin and stipe. Holotype :— CHINA . Shanxi Province , Yicheng County , Shihe Forest Farm , 35°29’40’’N , 112°5’41’’E , elev. 1960 m , 20 August 2019 , on fallen wood in a forest of Pinus sp . , H . Liu LH 688 ( BJTC FM 649 ). Description:— Basidiomes growing singly or in clusters. Pileus 60–80 mm diam, plano-convex with inflexed or turned up margin, margin cracking with age, yellow-brown (#8b4513) to red-brown (#bb6528), densely covered with small, yellow-brown (#8b4513) to red-brown (#bb6528) fibrillose scales, margin of pileus red-violet (#c71585) with tints of soft pink (#de6fa1). Context not recorded. Lamellae 3.0–5.0 mm broad, crowded, adnate to subdecurrent, white to pale yellowish (#ffffeb), edge entire. Stipe 60–90 × 23–25 mm , cylindrical, straight to curved, smooth, at first whitish (#faebd7) to pale yellow (#ffffeb), then soft pink (#de6fa1) and moderate orange (#cc8236). Taste not recorded. Smell indistinct. Spore print white. Basidiospores [30/1/1] (4.5–) 5–6 (–7) × (3.0–) 3.5–4 (–4.5) μm; [Q = (1.33–) 1.42–1.67 (–1.75), avQ = 1.50 ± 0.14]; mostly ellipsoid, some oblong-ellipsoid, smooth, thin-walled, hyaline, or with one large oil droplet. Basidia 28–40 × 5–7 μm, (2–)4-spored, cylindrical to narrowly clavate, often slightly constricted in the median part, with basal clamp connection; sterigmata narrow 3–6 μm long. Cheilocystidia prominent, large, often in clusters, (40–) 60–90 × (14–) 16–28 μm, variable in size and shape, mostly narrowly clavate to sphaeropedunculate, but also fusiform or broadly ellipsoid slightly thick-walled, hyaline. Pleurocystidia abundant, 38–50 × 5–6.5 μm, cylindrical or narrowly clavate, slightly flexuose, hyaline, thin-walled. Lamellar trama composed of regular, parallel to subparallel long, cylindrical, or slightly inflated hyphae, 5–34 μm diam, hyaline or with a fine granular intracellular pigment. Pileipellis a cutis, composed of hyphae 2.5–16 μm diam with homogeneous pale yellow to bronze pigment, yellow-brown intraparietal pigment and hyphae becoming erect and forming fascicles at intervals. Stipitipellis a thin cutis of cylindrical hyphae of 4–15 μm diam, with hyaline to pale yellow-brown content. Clamp connections present in all tissues. Habit, habitat and distribution:—single or grouped on the trunk of a dead tree in a forest of Pinus sp . , to date only known from Shanxi Province , China .