Porpomyces submucidus F. Wu & C.L. Zhao, 2015

Wu, Fang, Yuan, Yuan & Zhao, Chang-Lin, 2015, Porpomyces submucidus (Hydnodontaceae, Basidiomycota), a new species from tropical China based on morphological and molecular evidence, Phytotaxa 230 (1), pp. 61-68 : 65-66

Porpomyces submucidus F. Wu & C.L. Zhao , sp. nov. ( Figs. 4 , 5 )

MycoBank MB 812857

Differs from Porpomyces mucidus Jülich by smaller pores (7–9 per mm) and basidiospores (2.2–2.8 × 1.2–1.8 μm).

Type.— CHINA. Hainan Province, Ledong County, Jianfengling Nature Reserve, on fallen rotten angiosperm wood, 17 June 2014, Y.C. Dai 13708 (holotype, BJFC 017445).

Etymology.— Submucidus (Lat.) referring to the resemblance with Porpomyces mucidus .

Basidiome. —Annual, resupinate, up to 20 cm long, 5 cm wide, and 0.5 mm thick at the centre, soft when fresh, without odour or taste; becoming soft corky upon drying, sterile margin, cottony to rhizomorphic, thinning out, up to 2 mm. Pore surface white when fresh, becoming cream to buff when dry; pores round to angular, 7 – 9 per mm; dissepiments thin, mostly even. Subiculum white, soft corky, very thin, about 0.1 mm thick. Tubes buff, soft corky, up to 0.4 mm long.

Hyphal structure. —Hyphal system monomitic; generative hyphae smooth, all septa with clamp connections, usually ampullate; hyphae unchanged in KOH.

Subiculum.— Generative hyphae hyaline, thin- to slightly thick-walled, frequently branched with abundant clamp connections, loosely interwoven, IKI–, CB–, 2.5–4 μm in diam.

Tubes. —Tramal hyphae hyaline, thin-walled, frequently branched with abundant clamp connections, loosely interwoven, IKI–, CB–, 2–3 μm in diam. Cystidia and cystidioles absent; basidia barrel-shaped, thin-walled with a basal clamp and four sterigmata, 6–7 × 4–5 μm; basidioles in shape similar to basidia, slightly smaller.

Spores. —Basidiospores ellipsoid, hyaline, thin-walled, smooth, tapering towards the apiculus, IKI–, CB–, (2–)2.2–2.8(–3) × 1.2–1.8(–2) μm, L = 2.36 μm, W = 1.53 μm, Q = 1.54 (n=30/1).

Additional specimens examined.— Porpomyces submucidus . CHINA. Hainan Province, Ledong County, Jianfengling Nature Reserve, on fallen rotten angiosperm wood, 17 November 2007, B.K. Cui 5183 (BJFC 003224). Porpomyces mucidus . CHINA. Shanxi Province, Jiaocheng County, Pangquangou Nature Reserve, on fallen trunk of Picea , 12 October 2004, Yuan 860 (BJFC 000401). ITALY. Rome, Castal Fusano, on rotten wood of Pinus , 26 April 2005, Dai 6549 (BJFC 000403). FINLAND. Etelä-Häme, Lammi Biological Station, on fallen trunk of Betula , 8 October 1992, Dai 222 (BJFC 000402). Rigidoporus minutus . CHINA. Hainan Province, Baoting County, Diaoluoshan Nature Reserve, on rotten angiosperm, 14 June 2014, Dai 13602A (BJFC017341), Dai 13605A (BJFC017344).

Remarks. — Porpomyces submucidus is rather similar to P. mucidus , but the latter has larger pores as 4–5 per mm, fusoid cystidioles, presence of large crystals among hyphae and hymenia, and larger basidiospores measuring (2.7–) 2.8–3.9(–4.4) × (1.9–)2–2.8(–3) μm, L = 3.2 μm, W = 2.3 μm, Q = 1.3–1.4 ( Niemelä 2005). In addition, Porpomyces mucidus has a wide distribution in temperate areas in north hemisphere ( Gilbertson & Ryvarden 1986, Núñez & Ryvarden 2001, Dai 2012, Ryvarden & Melo 2014), while Porpomyces submucidus is found in tropical forest in Southern China so far.

Figures

FIGURE 4. Porpomyces submucidus (holotype). A basidiocarp.

FIGURE 5. Microscopic structures of Porpomyces submucidus (holotype). a: Basidiospores. b: Basidia and basidioles. c: Hyphae from trama. d: Hyphae from subiculum.