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

Figs 2A , 3

Diagnosis.

Differs from other Boletopsis species by largest basidiocarps (up to 18 cm in diam) with grayish brown to dark gray upper surface, gloeoplerous hyphae present in context, guttulate basidiospores, and the fact that it grows in forests of Pinus yunnanensis at high altitude with open and slightly dry environments in SW China.

Holotype.

China, Yunnan Province, Nujiang, Lanping County, Xinshengqiao National Forest Park, on ground in forest of Pinus yunnanensis , alt. 3000 m, 2 September 2021, Dai 22728 (BJFC037301).

Etymology.

Macrocarpa (Lat.): referring to the species having largest basidiocarps.

Fruiting bodies.

Basidiocarps annual, terrestrial, centrally stipitate, solitary. Pilei circular or irregular, slightly depressed at center, with undulate and sharp margin, up to 18 cm in diam and 3 cm thick at center when fresh. Pileal surface grayish brown (5/6E4) with cream margin (4A2/3) when fresh, becoming blackish blue (20F8) to black upon drying, smooth, azonate. Pore surface white when fresh, becoming clay-buff (6D4) to fawn (7D/E4) upon drying; pores round to angular, some irregular, 1-3 per mm, mature pores bigger than juvenile ones; dissepiment thin, even to slightly lacerate. Context white when fresh, become pale mouse-gray (7C2) when dry, brittle, up to 2.5 cm thick when fresh. Tubes concolorous with pore surface, brittle, up to 5 mm long when fresh. Stipe pale ash-gray (19C2) when fresh, become mouse-gray (9F3) when dry, up to 6 cm long and 4 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- to thick-walled, 4-9 μm in diam; gloeoplerous hyphae rarely present; tissue darkening in KOH.

Context.

Contextual hyphae hyaline, thick-walled, rarely branched, interwoven, distinctly inflated, 5-25 μm in diam; gloeoplerous frequently hyphae present, thin-walled, reflective in Melzer’s reagent.

Stipitipellis.

Stipitipellis hyphae hyaline, usually thick-walled with a wide lumen, rarely branched, parallel along stipe, straight, uniform, 4-12 μm in diam; gloeoplerous hyphae rarely present.

Tubes.

Tramal hyphae hyaline, thin-walled, occasionally branched, interwoven, uniform, 2-4 μm in diam; gloeoplerous hyphae rarely present; cystidia and cystidioles absent; basidia clavate, tetrasterigmatic with a basal clamp connection, 14-19 × 6-7 μm.

Spores.

Basidiospores angular to tubercular with irregular ornaments, hyaline, thin-walled, with a guttule, IKI-, CB-, (4.5-)4.8-6(-6.2) × (3.7-)4-5 μm, L = 5.22 μm, W = 4.31 μm, Q = 1.20-1.22 (n = 90/3).

Additional specimens examined (paratypes).

China, Yunnan Province, Chuxiong, Wuding County, on ground in forest of Pinus yunnanensis , alt. 2400 m, 23 September 2021, Dai 23064 (BJFC037635), Dai 23065 (BJFC037636); Dali, Jianchuan County, Laojunshan Nature Reserve, on ground in forest of Pinus yunnanensis , alt. 3100 m, 29 August 2020, Dai 21780 (BJFC035681); Nujiang, Lanping County, Luoguqing Nature Reserve, on ground in forest of Pinus yunnanensis , alt. 3000 m, 3 September 2021, Dai 22748 (BJFC037321); Xinshengqiao National Forest Park, on ground in forest of Pinus yunnanensis , alt. 3000 m, 2 September 2021, Dai 22727 (BJFC037300), Dai 22729 (BJFC037302).

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 3. Microscopic structures of Boletopsis macrocarpa (Holotype) a basidiospores b basidia c stipitipellis hyphae d pileipellis hyphae e hyphae from context f hyphae from trama.