Megasporia tropica Y. Yuan, X.H. Ji & Y.C. Dai

Yuan, Yuan, Ji, Xiao-Hong, Chen, Jia-Jia & Dai, Yu-Cheng, 2017, Three new species of Megasporia (Polyporales, Basidiomycota) from China, MycoKeys 20, pp. 37-50 : 40-41

Megasporia tropica Y. Yuan, X.H. Ji & Y.C. Dai sp. nov. Figure 3

Diagnosis.

Differs from other Megasporia species by strongly dextrinoid skeletal hyphae, and by lacking dendrohyphidia, cystidioles and hyphal pegs.

Holotype.

CHINA. Hainan Prov., Wuzhishan County, Wuzhishan Nature Reserve, on fallen angiosperm branch, 10 Nov 2015, B.K. Cui 13660 (BJFC022532).

Basidiocarps.

Annual, resupinate, corky, without odor or taste when fresh, becoming hard corky to leathery upon drying, up to 5 cm long, 3 cm wide, and 1.5 mm thick at centre. Sterile margin thinning out, cream when dry, up to 1 mm wide. Pore surface clay-pink to fawn when dry; pores round, 2-3 per mm; dissepiments thin, entire to lacerate. Subiculum cream, corky, up to 0.5 mm thick. Tubes clay-pink, slightly darker than subiculum, corky, up to 1 mm long.

Hyphal structure.

Hyphal system dimitic; generative hyphae bearing clamp connections; skeletal hyphae strongly dextrinoid, CB+; tissues unchanged in KOH.

Subiculum.

Generative hyphae infrequent, hyaline, thin-walled, occasionally branched, 2.5-3 µm in diam; skeletal hyphae dominant, thick-walled with a narrow to medium lumen, unbranched, more or less flexuous, loosely interwoven, 3-4 µm in diam.

Tubes.

Generative hyphae hyaline, thin-walled, occasionally branched, 1.5-2 µm in diam; skeletal hyphae dominant, thick-walled with a narrow lumen, occasionally branched, more or less straight, subparallel along the tubes, 2-3 µm in diam. Hyphal pegs, dendrohyphidia and cystidia absent; cystidioles present, subulate, thin-walled, smooth. Basidia broadly clavate, with four sterigmata and a basal clamp connection, sometimes with a big guttule, 20-25 × 7-9.5 µm; basidioles pear-shaped, slightly smaller than basidia. Small tetrahedric or polyhedric crystals frequently present among subhymenium and hymenium.

Spores.

Basidiospores cylindrical, hyaline, thin-walled, smooth, mostly with a big guttula, IKI–, CB–, (14.2 –)14.7–18.8(– 19.7) × (4.9 –)5–6.5(– 7.1) μm, L = 16.55 μm, W = 5.65 μm, Q = 2.83-3.04 (n = 60/2).

Additional specimen (paratype) examined.

CHINA. Hainan Prov., Ledong County, Jianfengling Forest Park, on fallen angiosperm branch, 21 Nov 2015, B.K. Cui 13740 (BJFC022533).

Etymology.

Tropica (Lat.): referring to the species occurring in the tropics.