Bjerkandera minispora Y.C. Dai & Chao G. Wang, 2021

Wang, Chao-Ge, Vlasak, Josef & Dai, Yu-Cheng, 2021, Phylogeny and diversity of Bjerkandera (Polyporales, Basidiomycota), including four new species from South America and Asia, MycoKeys 79, pp. 149-172 : 149

Bjerkandera minispora Y.C. Dai & Chao G. Wang sp. nov. Figs 6 , 7

Diagnosis.

The tiny pores (6-9 per mm), and ellipsoid small basidiospores measuring 3.1-4.2 × 2-2.8 μm set this species apart from others in Bjerkandera .

Type.

China. Hainan Province, Wuzhishan County, Wuzhishan Nature Reserve , 18°54'N, 109°42'E, fallen angiosperm trunk, 31. V. 2015, Y.C. Dai 15234 (holotype BJFC019345) .

Etymology.

Minispora (Lat.): referring to the species having small basidiospores.

Basidiomata.

Annual, pileate, solitary or imbricate, soft corky, without odor or taste when fresh, becoming corky when dry. Pilei flabelliform, projecting up to 4 cm, 5 cm wide and 3 mm thick at base. Pileal surface pinkish-buff to buff, becoming dark when touched, velutinate to glabrous, azonate; margin a bit acute. Pore surface buff-yellow, ash-grey to pale brown when dry, touched or bruised parts becoming almost black; sterile margin distinct, up to 1.5 mm wide; pores tiny, round to angular, 6-9 per mm; pores mouth sometimes with white tomentum; dissepiments thin, entire to lacerate. Context cream to pinkish-buff, corky, up to 2 mm thick. Tubes concolorous with the pore surface, darker than context, corky, up to 1 mm long, with a distinct dark line between tubes and context.

Hyphal structure.

Hyphal system monomitic; generative hyphae with clamp connections, smooth, hyaline to pale yellow, CB+, IKI-; tissues becoming dark in KOH.

Context.

Generative hyphae thick-walled with a wide lumen, moderately branched, loosely interwoven, 3.5-6 μm in diam.

Tubes.

Generative hyphae thin-walled, frequently branched, agglutinated and loosely interwoven, 2.5-3.5 μm in diam. Cystidia and cystidioles absent. Basidia clavate, sometimes with an intermediate constriction, with four sterigmata and a basal clamp connection, 9.5-11.5 × 4-5 μm; basidioles of similar shape to basidia, but smaller.

Basidiospores.

Oblong-ellipsoid to ellipsoid, hyaline, thin-walled, smooth, often with one or more guttules, CB-, IKI-, (3-)3.1-4.2(-4.8) × 2-2.8(-3) µm, L = 3.64 μm, W = 2.4 μm, Q = 1.49-1.54 (n = 60/2).

Additional specimen (paratype) examined.

China. Hainan Province, Wuzhishan County, Wuzhishan Nature Reserve, 18°54'N, 109°42'E, fallen angiosperm trunk, 24. XI. 2007, B.K. Cui 5376 (BJFC003417).

Remarks.

The buff-yellow pore surface, darkening when touched or bruised, the small pores (6-9 per mm) sometimes with white tomentum, and the ellipsoid small basidiospores (3.1-4.2 × 2-2.8 μm) set this species apart from others in Bjerkandera . Bjerkandera albocinerea resembles B. minispora by oblong-ellipsoid to ellipsoid basidiospores, but the former has sordid white fresh pileal surface, and dark brownish grey pore surface ( Motato-Vásquez et al. 2020). Bjerkandera ecuadorensis is similar to B. minispora in having pinkish-buff to buff pileal surface and round to angular pores (6-9 per mm), but the former has grey to dark-brown pore surface and bigger basidiospores measuring 3.9-4.5 × 2.7-3 μm.

Figures

Figure 6. Bjerkandera minispora (holotype, Y. C. Dai 15234) A basidiomata B poroid surface detail C a dark line between tubes and context. Scale bars: 1 cm (A); 1 mm (B, C).

Figure 7. Microscopic structures of Bjerkandera minispora (holotype, Y. C. Dai 15234) a basidiospores b basidia and basidioles c hyphae from trama d hyphae from context.