Phanerochaete canobrunnea Sheng H. Wu, C.C. Chen & C.L. Wei sp. nov. Figs 3A, 4

Diagnosis.

Phanerochaete canobrunnea is recognised by brown generative hyphae and brown skeletal hyphae, in combination with absence of cystidia.

Holotype.

TAIWAN. Nantou County: Yuchih Township, Lienhuachih, 23°55'N, 120°53'E, 715 m alt., on angiosperm branch, coll. W.C. Chen, C.C. Chen & C.L. Wei, 23 Jun 2015, CHWC 1506-17 (TNM F0029207).

Etymology.

From canus+brunneus (= greyish-brown), referring to the colour of the hymenial surface.

Description.

Basidiome resupinate, effuse, loosely adnate, membranaceous, 250-500 μm thick in section. Hymenial surface pale greyish-brown, slightly darkening in KOH, smooth, sometimes cracked; margin concolorous or brownish, slightly fibrillose or determinate.

Hyphal system dimitic; generative hyphae mostly simple-septate, single or double clamp connections occasionally present in subiculum. Subiculum fairly uniform, with fairly loose texture, 200-400 μm thick; generative hyphae interwoven, brown, more or less straight, moderately ramified, rarely encrusted, 4-9 (-11) μm diam., thin- to thick-walled, walls up to 1.5 μm thick, anastomoses occasional; skeletal hyphae interwoven, brown, more or less straight, un-ramified or ramified, 2-5 μm diam., usually subsolid or thick-walled, walls up to 1.5 μm, adventitious septa occasionally present. Hymenial layer thickening, with dense texture, 50-100 μm thick; hyphae more or less vertical, brownish to subcolourless, 3-6 μm diam., thin-walled. Cystidia lacking. Basidia subclavate to clavate, 15-25 × 5-6 μm, 4-sterigmate. Basidiospores ellipsoid to narrowly ellipsoid, adaxially flattened, smooth, thin-walled, IKI -, CB -, mostly 4.2-5.8 × 2.5-3 μm . [(4-) 4.5-5.8 (-6) × (2.5-) 2.7-3 (-3.2) μm, L = 5.10 ± 0.54 μm, W = 2.86 ± 0.18 μm, Q = 1.78 (n = 30) (CHWC 1506-17); (4-) 4.2-5 (-5.8) × (2.3-) 2.5-2.8 (-3) μm, L = 4.63 ± 0.42 μm, W = 2.66 ± 0.17 μm, Q = 1.75 (n = 30) (CHWC 1506-39)].

Additional specimens examined (paratypes).

TAIWAN. Nantou County: Yuchih Township, Lienhuachih, 23°55'N, 120°53'E, 715 m alt., on angiosperm branch, coll. W.C. Chen, C.C. Chen & C.L. Wei, 23 Jun 2015, CHWC 1506-39 (TNM F0029217); CHWC 1506-66 (TNM F0029236).

Distribution.

Known from subtropical Taiwan.

Remarks. Amongst the few species in Phanerochaete having brown subicular hyphae, only P. canobrunnea and P. thailandica possess skeletal hyphae [described as "quasi-binding hyphae" in the protologue of P. thailandica, Sadlikova and Kout (2017)]. These two species are also closely related according to the phylogenetic analyses (Fig. 2). However, P. thailandica bears leptocystidia and has larger basidiospores (7-8 × 4-4.5 µm) (Sadlikova and Kout 2017). Phanerochaete brunnea Sheng H. Wu resembles P. canobrunnea in lacking cystidia and having similar basidiospores, but its hyphal system is monomitic (Wu 1990). These two species are phylogenetically not closely related (Fig. 2).