Neomensularia rectiseta X.H. Ji, L.W. Zhou & F. Wu

MycoBank 818173 Facesoffungi number: 02937

Etymology – Rectiseta (Lat.): referring to the rectus setae of the species.

Basidiocarps perennial, pileate, corky and without odour or taste when fresh, hard corky when dry. Pilei fan-shaped, projecting up to 12 cm, 5 cm wide and 2 cm thick at center. Pileal surface dark grey and margin buff-yellow, with distinctly concentric zones in different shades; margin acute. Pore surface dark brown to fuscous; sterile margin very narrow to almost lacking; pores circular, 8–9 per mm; dissepiments thick, entire. Context dark brown, up to 3 mm thick, duplex, separated by one black line. Tubes yellowish brown, distinctly paler than pores and context, up to 17 mm thick, tube layers distinctly stratified with intermittent context layers, individual tube layer up to 4 mm long.
Hyphal structure – Hyphal system dimitic; generative hyphae simple septate; skeletal hyphae dominant; tissue darkening but otherwise unchanged in KOH. Context – Generative hyphae pale yellowish, slightly thick-walled, rarely branched, occasionally simple septate, 3–4 mm in diameter; skeletal hyphae dominant, yellowish to golden brown, thick-walled with a narrow to wide lumen, unbranched, interwoven, 3–5 μm diameter.
Tubes – Generative hyphae hyaline to pale yellow, thin- to slightly thick-walled, rarely branched, frequently simple septate, 2–4 mm in diameter; skeletal hyphae dominant, pale yellow, thick-walled with a wide to narrow lumen, unbranched, aseptate, loosely interwoven, 2.5–4 mm in diam. Setae frequent, subulate with a straight tip, arising from hymenium, dark brown, thick-walled, 15–25 × 6–12 μm; cystidia absent; fusoid cystidioles occasionally present; basidia more or less barrel-shaped, with four sterigmata and a simple septum at the base, 7–12 × 4–5 μm; basidioles in shape similar to basidia, but slightly smaller. Spores – Basidiospores ellipsoid, yellowish brown, thick-walled, smooth, IKI–, CB+, (3.4–)3.5–4.0(–4.2) × (2.5–)2.7–3.0(–3.1) μm, L = 3.79 μm, W = 2.79 μm, Q = 1.30–1.42 (n = 60/2).

Material examined – CHINA. Hunan, Yizhang County, Mangshan Natural Reserve, on dead angiosperm tree, 16 August 2014, Dai 15136 (Holotype in BJFC). CHINA. HUNAN: Yizhang County, Mangshan Natural Reserve, on fallen angiosperm tree, 16 August 2014, Dai 15129 (BJFC) (paratype).

Phylogeny of Neomensularia inferred from LSU dataset. The topology is from the maximum likelihood method with bootstrap values from the maximum likelihood method and Bayesian posterior probabilities from Bayesian inference method, if simultaneously above 50% and 0.8, respectively, at the nodes. The newly sequenced specimens from species of Neomensularia are in boldface.

Phylogeny of Neomensularia inferred from ITS dataset. The topology is from the maximum likelihood method with bootstrap values from maximum likelihood method and Bayesian posterior probabilities from Bayesian inference method, if simultaneously above 50% and 0.8, respectively, at the nodes. The newly sequenced specimens from species of Neomensularia are in boldface.

Basidiocarps of Neomensularia rectiseta (holotype). Bar: 10 mm.

Microscopic structures of Neomensularia rectiseta (drawn from the holotype). a: Basidiospores; b: Basidioles; c: Basidia; d: Cystidioles; e: Setae; f: Hyphae from trama; g: Hyphae from context.