Boletellus wenshanensis G. Wu & Xin Zhang, 2022

Zhang, Xin & Wu, Gang, 2022, A new species of Boletellus Section Chrysenteroidei (Boletaceae, Boletales) from southeast Yunnan, China, Phytotaxa 547 (2), pp. 177-185 : 181-184

Boletellus wenshanensis G. Wu & Xin Zhang , sp. nov.

Figs. 2–4

Mycobank: MB 842992

Typification: CHINA. Yunnan Province: Wenshan Zhuang and Miao Autonomous Prefecture , Malipo County, Mengdong Town , Yezhutang Village , 22.845431°N, 104.718466°E, 1380 m elev., 29 July 2017, 532624MF-202- Wu2281 (holotype, KUN-HKAS 122938!)

Diagnosis: Distinguished by the rapid dark blue reaction on all parts of the fruitbody when bruised, uncracked brown to brownish orange pileus, scaly stipe covered with brownish orangy punctate squamules, yellow hymenophore, intricate trichodermal pileipellis, ellipsoid to broadly fusoid basidiospores ornamented with longitudinal ridges, and hyphohymeniform stipitipellis.

Etymology: wenshanensis (Lat.) , refers to the type locality of this species.

Description:— Pileus 4–9 cm diam, convex to broadly convex; brown (7D2), grayish orange to brownish orange (5B3–5C3), subtomentose, not cracked when mature, dry, sterile margin present and often involute; context up to 5–10 mm thick, pale yellow (4A3), quickly changing to blue then blackish blue on exposure. Hymenophore sinuate, up to 4–8 mm thick; pore surface and tubes concolorous, light yellow to grayish yellow (4A5–4B5), quickly staining dull blue to blackish blue when bruised; pores irregular to roundish, 1.5–1 per mm. Stipe 6.5–10 cm long, 6–15 mm diam, central, subcylindrical to slightly obclavate, firm, solid; surface pale yellow to light yellow (4A3–4A5), covered with golden yellow, orange to brownish yellow (5B7–5B8–5C7) punctate squamules, staining dark blue when touched; context firm, light yellow to maize yellow (4A5–4A6), quickly staining dark blue on exposure. Basal mycelium white to dirty white.

Basidiospores [63/3/2] 12.0–15.5 (17.0) × 6.0–8.0 μm [Q = (1.71)1.75–2.16 (2.23), Q m = 1.96 ± 0.14], ellipsoid to broadly fusiform and inequilateral in side-view, with suprahilar depression, ellipsoid to ovoid in face-view, brownish in 5 % KOH, ornamented with longitudinal ridges, thick-walled. Basidia 28–44 × 12–16 μm, broadly clavate, 4-spored, rarely 2-spored. Cheilocystidia 28.5–45.0× 8.0–11.0 μm, sparse, subfusoid to ventricose, thin-walled. Pleurocystidia 32–67 × 8–18 μm, sparse, subfusoid to broadly ventricose, sometimes with long beaks, thin-walled. Hymenophoral trama phylloporoid with hyphae of the lateral strata touching or almost touching each other; hyphae subcylindrical to cylindrical, 5–15 μm wide. Pileipellis an intricate trichoderm, about 400 μm thick, composed of entangled filamentous hyphae 6–12 μm wide, thin-walled, with subcylindrical to subclavate terminal cells 28–78 × 5–10 μm, thin-walled. Pileal trama composed of interwoven hyphae 5–13 μm wide. Stipitipellis about 150 μm thick, hyphohymeniform with clavate to cystidioid terminal cells (18.0–45.0 × 8.5–14.0 μm) in the inner layer and narrow cylindrical terminal cells (25.0–56.0 × 4.5–7.5 μm) in the outter layer. Stipe trama composed of longitudinally arranged parallel thin-walled hyphae 5–20 μm wide. Clamp connections absent.

Ecology, habitat and distribution:—On soil in broad-leaved forests dominated by Fagaceae trees ( Lithocarpus spp ., Castanopsis spp ., etc.) mixed with fir, waxberry and bamboos. China. June to August. Currently only known in southeast Yunnan of China.

Other specimen examined:— CHINA. Yunnan Province: Wenshan Zhuang and Miao Autonomous Prefecture , Malipo County, Liuhe Town , Jiaowan Village , 23.344895°N, 104.9048°E, 888 m elev., 25 June 2017, 532624MF-205- Wu2042 (KUN-HKAS 122937) .

Figures

FIGURE 2. Fruitbodies and habitat of Boletellus wenshanensis in the field. a–b: KUN-HKAS 122938; c–e: KUN-HKAS 122937; f: habitat of B. wenshanensis. Bars = 2 cm.

FIGURE 3. Basidiospores under SEM of Boletellus wenshanensis. a–f: KUN-HKAS 122938, g–i: KUN-HKAS 122937.

FIGURE 4. Microscopic features of Boletellus wenshanensis (a, c–g: KUN-HKAS 122938, holotype; b, h: KUN-HKAS 122937). a. Pileipellis; b. Terminal cells of pileipellis; c. Cheilocystidia; d. Pleurocystidia; e. Basidia; f. Basidia, pleurocystidium and basidioles; g. Stipitipellis; h. Pleurocystidia. Bars = 10 μm.