Sidera minutissima Y.C. Dai, F. Wu, G.M. Gates & Rui Du, 2020

Du, Rui, Wu, Fang, Gate, Genevieve M., Dai, Yu-Cheng & Tian, Xue-Mei, 2020, Taxonomy and phylogeny of Sidera (Hymenochaetales, Basidiomycota): four new species and keys to species of the genus, MycoKeys 68, pp. 115-135 : 115

Sidera minutissima Y.C. Dai, F. Wu, G.M. Gates & Rui Du sp. nov. Figures 4 , 5

Type material.

Holotype: Sri Lanka. Wadduwa, South Bolgoda Lake, on rotten angiosperm branch, 28 Feb 2019, Y.C. Dai 19529 (BJFC, isotype in University of Ruhuha).

Etymology.

Minutissima (Lat.), refers to the species having small basidiomata.

Description.

Basidiomata: Annual, resupinate, soft when fresh, soft corky to fragile when dry, up to 5 cm long, 3 cm wide, and approximately 1 mm thick at center; pore surface bluish to more or less turquoise when fresh, becoming cream to buff yellow when dry; sterile margin distinct, fimbriate, thinning out; pores round, 7-9 per mm; dissepiments thin, entire; subiculum very thin to almost absent; tubes concolorous with pore surface, up to 1 mm long.

Hyphal structure: Hyphal system dimitic, generative hyphae bearing clamp connections; skeletal hyphae unbranched, interwoven, 2-3 μm diam; all hyphae IKI-, CB-,unchanged in KOH.

Subiculum : Generative hyphae hyaline, thin-walled, frequently branched, 1-2 µm in diam; skeletal hyphae dominant, more or less straight, unbranched, interwoven, 2-3 μm diam; rosette-like crystals frequently present, 2-8.5 µm in diam, some irregular rhomboidal crystals present.

Tubes: Generative hyphae hyaline, thin-walled, frequently branched, 1-2 µm in diam, some with swollen tips, dominating at dissepiment edges; skeletal hyphae with a narrow lumen to subsolid, unbranched, interwoven, 2-3 µm diam; rosette-like and irregular rhomboidal crystals abundant; cystidioles present, fusoid, hyaline, thin-walled, basally swollen, some with a long or hyphoid neck, 8-18 × 2-5 μm; basidia barrel-shaped, hyaline, bearing four sterigmata and a basal clamp connection, 7.1-12 × 3.5-4.8 μm; basidioles in shape similar to basidia, but slightly shorter.

Basidiospores: Allantoid, hyaline, thin-walled, smooth, occasionally with one or two guttules, IKI-, CB-, (3.7-)3.8-4.4(-4.5) × (0.8-)0.9-1.3 μm, L = 4.02 μm, W = 1.07 μm, Q = 3.67-3.85 (n = 60/2).

Additional specimen examined (paratype).

Sri Lanka. Kandy, Udawatta kele, Royal Forest Park. on rotten angiosperm wood, 2 Mar 2019, Y.C. Dai 19587 (BJFC).

Figures

Figure 4. A basidioma of Sidera minutissima (paratype, Dai 19587). Scale bar: 1 cm. Photo by Yu-Cheng Dai.

Figure 5. Microscopic structures of Sidera minutissima (holotype, Dai 19529) a basidiospores b basidia, basidioles c cystidioles d hyphae from subiculum e hyphae from trama f hyphae at dissepiment edge. Drawings by Rui Du.