Mensularia rhododendri F. Wu, Y.C Dai & L.W. Zhou, 2015

Wu, Fang, Yang, Jiao & Zhou, Li-Wei, 2015, Mensularia rhododendri (Hymenochaetaceae, Basidiomycota) from southwestern China, Phytotaxa 212 (2), pp. 157-162 : 159-161

Mensularia rhododendri F. Wu, Y.C Dai & L.W. Zhou , sp. nov. ( Figs. 2 , 3 )

MycoBank MB 811985

Differs from Mensularia hastifera by smaller pores (5–6 per mm), thinner fruit body (up to 2.5 mm), and shorter hyphoid setae (up to 110 μm long) present in trama only.

Type:— CHINA. Guizhou Province: Jiangkou Country, Fanjingshan Nature Reserve, on dead tree of Rhododendron , 24 November 2014, Dai 14951 (holotype, BJFC!).

Etymology:— rhododendri (Lat.) referring to the host genus.

Fruitbody: — Basidiocarps annual, resupinate to effused-reflexed, not detachable, resupinate part up to 30 cm long and 8 cm wide, when fresh elastic tough, without odour or taste, when dry becoming corky. Pileus projecting up to 2 mm, 18 cm wide, and 2.5 mm thick. Pileal surface yellowish brown, finely velutinate to glabrous; margin pale yellow, blunt, curving down when dry. Pore surface pink-yellow to yellow, reflecting light when fresh, becoming grayish yellow when dry; sterile margin distinct, up to 1 mm wide; pores angular, 5–6 per mm; dissepiments thin, distinctly lacerate. Context umber brown, darker than tubes, hard corky, up to 0.5 mm thick. Tubes greyish brown, corky, up to 2 mm long.

Hyphal structure:—Hyphal system monomitic; generative hyphae simple septate; tissues darkening but otherwise unchanged in KOH.

Context:—Generative hyphae pale yellowish to golden yellow, thin- to slightly thick-walled with a wide lumen, infrequently branched and frequently simple septate, regularly arranged to loosely interwoven, 4–6 μm in diam.

Tubes:—Tramal hyphae hyaline to pale yellowish or golden yellow, thin- to fairly thick-walled with a large lumen, unbranched, with frequent simple septa, parallel along the tubes, 2.5–5 μm in diam. Hymenial setae frequent, dark brown, thick-walled, sharp-pointed, 16–40 × 6.5–8 μm, sometimes the root of a hymenial setae arises deep from trama; hyphoid setae infrequent, thick-walled with a narrow lumen, apex acute, 50–110 μm long, 8–13 μm in diam; cystidia and cystidioles absent; basidia barrel-shaped, with four sterigmata and a simple basal septum, 10–15 × 5–6.5 μm; basidioles in shape similar to basidia, but smaller.

Spores:—Basidiospores ellipsoid, hyaline to pale yellowish, fairly thick-walled, smooth, IKI–, CB+, (4.5–)4.6– 5.1 × 3.0–4.0 μm, L = 4.89 μm, W = 3.54 μm, Q = 1.38 (n=30/1).

Additional specimem: — CHINA. Guizhou Province: Jiangkou Country, Fanjingshan Nature Reserve, on dead tree of Rhododendron , 24 November 2014, LWZ 20141124-8 (paratype, IFP!).

Figures

FIGURE 2. Mensularia rhododendri (holotype).A basidiocarp. Photo by Li-Wei Zhou.

FIGURE 3. Microscopic structures of Mensularia rhododendri (holotype). a: Basidiospores. b: Basidia and basidioles. c: Setae and hyphoid setae. d: Hyphae from trama. e: Hyphae from subiculum. Drawings by Fang Wu.