Polyporus ulleungus H. Lee, N.K. Kim & Y.W. Lim

Index Fungorum number: IF552510 Facesoffungi number: FoF 2628

Etymology: very common on Ulleung Island.

Holotype: SFC20120814-41

Basidiocarps annual, central stipitate; Pileus circular, plane then infundibuliform, up to 110 mm wide, 3 mm thick; pileal surface light brown to dark blackish-brown in the center, fibrillose with flattened, radially striate, slightly glabrous, margin ochreous, sharp and undulate. Hymonophore white to brown; pores fine, rounded to angular, 5–6 per mm. Context in pileus pale buff, corky, up to 2 mm thick. Tube white and cream when young, ochreous with age or dry, up to 1 mm thick. Stipe central, brown to dark brownish-black, smooth to longitudinally wrinkled, apex distinct from the pore, upper portion of blackish stipe usually covered by pores, up to 30 mm long and 8 mm thick. Hyphal system dimitic; generative hyphae hyaline in KOH, thin-walled, 1.7–3 μm in diam., septa with clamps, skeletal-binding hyphae thick-walled, aseptate, much branched, with tapering apices, up to 6 μm diam. Cystidia absent. Basidia clavate, 4–sterigmate (up to 3.4 μm), 23.4–25.7 × 5.8–6.9 μm, with a basal clamp. Basidiospores cylindric, hyaline, smooth, IKI-, 6.8–8 × 2.3–3.3 μm. L = 7.06 μm, W = 2.85 μm, Q = 2.50 (n = 20/2).

Habitat: solitary to gregarious on dead wood of hardwood.

Material examined: KOREA, Gyeongsangbuk-do, Ulleung-gun, Na-ri basin, on fallen hardwood branch, 14 August 2012, Y.W. Lim, W. J. Kim & S-Y. Oh (SFC20120814-41, holotype); KOREA, Gangwon-do, Inje-gun, on fallen branch of Betula platyphylla var. japonica, 2 September 2015, Y. W. Lim & H. Lee (SFC20150902-99, paratype). GenBank numbers SFC20120814-41 ITS:KY038467. SFC20150902-99 ITS:KY038481.

Notes: Polyporus ulleungus is commonly found in the Na-ri Basin of Ulleung Island and has larger basidiocarps (SFC20120814-41; 110 mm across) than other species collected in inland area (SFC20150902-99; 35 mm across). Polyporus ulleungus is most similar to P. koreanus and P. melanpus. It has larger pore (5–6 mm) than those of P. koreanus (6–7 mm) and P. melanpus (6–8 mm). In a phylogenetic analysis, P. ulleungus formed a distinct clade with strong support (100% ML, and clearly separated from P. koreanus and P. melanpus.

Phylogram generated from maximum likelihood (RAxML) analysis based on ITS sequence data of Polyporus. Maximum likelihood bootstrap support values greater than 70% are indicated above or below the nodes and the new species is in bold. The tree is rooted with two Neofavolus species.


Polyporus ulleungus (SFC20120814-41, holotype). a, b Fruiting bodies in the field (SFC20120814-41). c Fruiting bodies in the field (SFC20150902-99). d Pores of fruiting body (SFC20120814-41). e Microscopic structure; basidiospores, basidia, generative hyphae and skeletal-binding hyphae.