Tricholomopsis galeata L. Fan & N. Mao, 2021

Mao, Ning, Xu, Yu-Yan & Fan, Li, 2021, Three new species of Tricholomopsis (incertae sedis) from North China based on morphological and molecular data, Phytotaxa 507 (2), pp. 155-166 : 160

Tricholomopsis galeata L. Fan & N. Mao , sp. nov. ( Figs. 2 , 3 )

MycoBank:—MB839211

Diagnosis:— Pileus 50–130 mm broad, light orange, covered with red fibrillose scales, basidiospores broadly ellipsoid to ellipsoid, Q = (1.11–) 1.25–1.67 (–2.0), cheilocystidia clavate-shaped, pleurocystidia absent.

Etymology:—‘ galeata ’, helmet, refers to the shape of pileus.

Holotype:— CHINA. Shanxi Province, Yicheng County, Shihe Forest Farm, 35°29’35’’N, 112°5’41’’E, elev. 1,960 m, 26 August 2020, on a dead tree trunk in a coniferous forest dominated by Pinus sp. , H. Liu LH 1196 ( BJTC FM1107 ).

Description:— Basidiomes growing singly or in clusters. Pileus 50–130 mm diam, helmet-like to convex with lightly inrolled margin, margin cracking with age, dry, light orange (#8b4513), densely covered with small, red to purple reddish (#e08796) fibrillose scales. Context yellowish, thin to slightly thick. Lamellae 3.5–5.5 mm broad, free to adnate, crowded, pale yellow (#ffffeb), edge entire; lamellulae in 3–4 tiers, concolorous with lamellae. Stipe 35–120 × 12–20 mm, cylindrical, hollow, straight to curved, smooth, dry, pale red (#ffcocb), pale orange (#ffe59a) to light orange (#8b4513), often staining purple especially when young. Taste not recorded. Smell indistinct. Spore print white.

Basidiospores [30/2/2] (4–) 5–7 (–8) × (3–) 4–5 (–6) μm; [Q = (1.11–) 1.25–1.67 (–2.0), avQ = 1.48 ± 0.21]; broadly ellipsoid to ellipsoid, smooth, thin-walled, hyaline, usually containing one large oil droplet. Basidia 30– 40 × 6–8 μm, (2–)4-spored, cylindrical to narrowly clavate; with basal clamp connection; sterigmata 4–7 μm long. Cheilocystidia prominent, large, often in clusters, (45–) 55–105 (–126) × 13–23 (–27) μm, mostly narrowly clavate to lageniform-fusiform, slightly thick-walled, hyaline, or filled with yellow granular pigment. Pleurocystidia absent. Lamellar trama regular, composed of parallel hyphae 3–18 μm diam, cylindrical to slightly inflated, hyaline or with a fine pale yellow (#ffffeb) granular intracellular pigmentation. Pileipellis a cutis, composed of densely arranged parallel hyphae, 3–10 μm diam, with yellow to brown intraparietal and homogeneous or finely granular intracellular pigment, hyphae becoming erect and forming fascicles at intervals. Stipitipellis a thin cutis of parallel cylindrical hyphae of 5–15 μm diam, with hyaline to pale yellow-brown content. Clamp connections present in all tissues.

Habit, habitat and distribution:—found growing on a dead tree trunk in a coniferous forest dominated by Pinus sp. , so far only known from Shanxi Province, China.

Additional specimens examined:— CHINA. Shanxi Province, Yicheng County, Shihe Forest Farm, 35°29’34’’N, 111°53’59’’E, elev. 1,927 m, 20 August 2019, on the trunk of a dead tree in a coniferous forest dominated by Pinus sp. , C . Yang YCM013 ( BJTC FM637 ). ibid. Yuanqu County, Lishan Mountain , Zhongcun Forest Farm , 35°29’7’’N, 112°25’5’’E, elev. 1,680 m, 15 July 2020, on fallen wood in a forest of Pinus sp. , H . Liu LH 919 ( BJTC FM1229 ) .

Figures

FIGURE 2. Basidiomes of the three new species. a. Tricholomopsis galeata (BJTC FM1107, holotype); b. Tricholomopsis pallidolutea (BJTC FM1184, holotype); c–d. Tricholomopsis mitirubicunda (BJTC FM649, holotype). Scale bars: a, c, d = 20 mm; b = 10 mm. Photos by: Li Fan.

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.