Boletopsis tibetana Y.C. Dai, F. Wu & H.M. Zhou, 2022

Zhou, Hong-Min, Zhao, Qi, Wang, Qi, Wu, Fang & Dai, Yu-Cheng, 2022, Two new species of Boletopsis (Bankeraceae, Thelephorales) from Southwest China, MycoKeys 89, pp. 155-169 : 155

Boletopsis tibetana Y.C. Dai, F. Wu & H.M. Zhou sp. nov.

Figs 2D-E , 4

Diagnosis.

Differs from other Boletopsis species by smaller pores (3-4 per mm), the presence of gloeoplerous hyphae in pileipellis and context, and the fact that it grows in the forest of Picea in Tibet, SW China.

Holotype.

China, Tibet, Linzhi, on ground in the forest of Picea balfouriana , alt. 2900 m, 23 August 2019, Dai 20896 (BJFC032554).

Etymology.

Tibetana (Lat.): referring to the species having a distribution in Tibet.

Fruiting bodies.

Basidiocarps annual, terrestrial, centrally stipitate, solitary to confluent. Pilei convex, or irregular, with undulate and incurved margin, up to 7 cm in diam and 1 cm thick at center when fresh. Pileal surface vinaceous buff (4C4) to clay buff (6D4) when fresh, becoming mouse-gray (9F3) to black upon drying, smooth, azonate; margin concolorous with pileal surface. Pore surface white when fresh, become fawn (7D/E4) when bruised, ash-gray (19C2) when dry; pores round to angular, 3-4 per mm; dissepiment thin, entire to slightly lacerate. Context white when fresh, become ash gray (19C2) when dry, rigid, up to 9 mm thick when dry. Tubes concolorous with pore surface, brittle, up to 1 mm long when dry. Stipe concolorous with pileal surface, cylindrical or tapering to the base, up to 6 cm long and 2 cm in diam when fresh.

Hyphal structure.

Hyphal system monomitic; generative hyphae with clamp connections; gloeoplerous hyphae present, usually 3-11 μm in diam.

Pileipellis.

Pileipellis hyphae hyaline, thin-walled, with finger-shaped tips, 5-7 μm in diam; gloeoplerous hyphae frequently present, thin-walled, strongly reflective in Melzer’s reagent; tissue darkening in KOH.

Context.

Contextual hyphae hyaline, thick-walled, rarely branched, interwoven, distinctly inflated, 6-22 μm in diam; gloeoplerous hyphae present, thin-walled, strongly reflective in Melzer’s reagent.

Stipitipellis.

Stipitipellis hyphae hyaline, thin- to thick-walled, frequently branched, subparallel along stipe, straight, uniform, 2-6 μm in diam; gloeoplerous hyphae rarely present.

Tubes.

Tramal hyphae hyaline, thin-walled, occasionally branched, loosely interwoven, uniform, 2-4 μm in diam; gloeoplerous hyphae rarely present; cystidia and cystidioles absent; basidia clavate, tetrasterigmatic with a basal clamp connection, 13-25 × 6-8 μm; basidioles clavate, 22-40 × 3-4 μm.

Spores.

Basidiospores angular to tubercular with irregular ornaments, hyaline, thin-walled, IKI-, CB-, 5-6.5(-7) × 4-5(-5.2) μm, L = 5.55 μm, W = 4.41 μm, Q = 1.22-1.29 (n = 60/2).

Additional specimen examined (paratype).

China, Tibet, Linzhi, on ground in forest of Picea balfouriana , alt. 2900 m, 23 August 2019, Dai 20897 (BJFC032555).

Figures

Figure 2. Basidiocarps of Boletopsis in China A B. macrocarpa (Dai 22728) B B. sp. 1 (Dai 22172) C B. cf. grisea (Dai 23070) D-E B. tibetana (Dai 20896 and Dai 20897).

Figure 4. Microscopic structures of Boletopsis tibetana (Holotype) a basidiospores b basidia and basidioles c stipitipellis hyphae d pileipellis hyphae e hyphae from context f hyphae from trama.