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

Boletopsis tibetana Y. C. Dai, F. Wu & H. M. Zhou, 2022 Materials Type status: Other material. Occurrence: recordNumber: Bang Feng 1680; recordedBy: Bang Feng; individualID: KUN-HKAS 94064; occurrenceID: B7750492-4BE1-55F6-9AD7-B61D18FA7558; Taxon: scientificName: Boletopsis tibetana; kingdom: Fungi; phylum: Basidiomycota; class: Agaricomycetes; order: Thelephorales; family: Bankeraceae; genus: Boletopsis; Location: higherGeographyID: East Asia; China; Tibet; county: Linzhi; locality: Lulang Town, Bayi, Zhaxigang Village; verbatimElevation: 3350 m; Event: eventDate: 2014-08-01 Description Basidiomata annual, medium, centrally stipitate, solitary to gregarious (Fig. 1 f). Pileus up to 12 cm in diameter, convex or irregular, clay buff (5 C 3) to dark brown (5 F 7), becoming greyish-brown (4 C 3) to black when dry; margin undulate and incurved. Context white (1 A 1), becoming pale brown (1 B 3) when dry. Hymenophore slightly decurrent, surface white (1 A 1), becoming clay buff (6 D 4) to fawn (7 D / E 4) when dry; hymenophoral pores round to angular or irregular, 1–4 per mm; tubes concolorous with hymenophoral surface, darkening when bruised. Stipe up to 9 cm long and 2 cm wide, solid, subcylindrical or tapering towards the base, concolorous with pileal surface. Hyphal system monomitic. Generative hyphae with clamp connections. Basidia thin-walled, 19–25 (35) × 8–11 μm, clavate to cylindrical, sometimes flexuous or ventricose with a peduncle, 4 - spored, clamped at base, hyaline in KOH (Fig. 5 a). Basidiospores [20 / 1 / 1] 5–6 (6.5) × 4–5.5 (6) μm, Q = 1–1.25 (1.5), Q m = 1.12 ± 0.13, globose to oblong, acyanophilic and non-dextrinoid, hyaline to pale yellow in KOH; ornamentation on the surface tuberculate and sometimes furcate (Fig. 3 e, f; Fig. 5 b). Cystidia absent. Tube tramal hyphae thin-walled, 2–4 μm wide, cylindrical, sometimes branched, interwoven and occasionally subparallel in a bunch, hyaline in KOH. Hyphae of pileipellis thin-walled, 4–10 μm wide, cylindrical with finger-shaped tips, sometimes branched, interwoven, faint olivaceous in KOH; terminal cells (37) 47–77 × 4–6 μm (Fig. 5 c). Pileal tramal hyphae thin-walled, 6–30 μm wide, inflated, rarely branched, interwoven and occasionally subparallel in a bunch, hyaline in KOH. Hyphae of stipitipellis thin-walled to slightly-thick wall (up to 0.7 μm thick), 2–8 μm wide, cylindrical, interwoven, frequently branched, hyaline in KOH. Distribution Currently known from Tibet, China. Ecology Growing on the ground in forests dominated by trees of the families Fagaceae (Quercus sp.) and Pinaceae (Picea balfouriana) or in pure Picea forests dominated by P. balfouriana at an altitude ranging from 2900 m to 3350 m. Notes Boletopsis tibetana is characterised by its clay buff to dark brown pileus, gloeoplerous hyphae in pileipellis and context, solitary to gregarious in mixed forests dominated by Picea and Quercus or in pure Picea forests at an altitude ranging from 2900 m to 3350 m. Boletopsis tibetana resembles B. leucomelaena by its solitary to gregarious habitat, frequently branched hyphae of stipitipellis and distribution in forests dominated by tres of the genus Picea. However, B. leucomelaena has greyish sepia or black-brown pileus often with a tinge of magenta, large pores (1–3 per mm) and a distribution in Europe (Niemelä and Saarenoksa 1989). In our re-examination of B. tibetana, we found wider basidia (19–35 × 8–11 μm) than those in the protologue (13–25 × 6–8 μm) (Zhou et al. 2022).