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

Index Fungorum number: IF552509 Facesoffungi number: FoF 00556

Etymology: referring to the first reported species of this genus found in Korea.

Holotype: SFC20150813-58

Basidiocarps annual, central stipitate; Pileus circular, plane and somewhat depressed, funnel-shaped in the center, up to 70 mm in diam., 2 mm thick; pileal surface light grey to pale buff, with age becoming brown and dark brown, fibrillose with flattened, radially striate, slightly glabrous; margin ochreous, sharp and undulate. Hymonophore white, cream, buff to brown; pores fine, rounded to angular, 6–7 per mm. Context in pileus pale buff, corky, up to 1.5 mm thick. Tube slightly darker than context, up to 0.5 mm thick. Stipe central, brown, dark reddish-brown to black, smooth to longitudinally wrinkled, apex distinct from the pore, upper portion of blackish stipe usually covered by pores, up to 50 mm long and 9 mm thick. Hyphal system dimitic; generative hyphae hyaline in KOH, thin-walled, 2.8–3.5 μm in diam., septa with clamps, skeletal-binding hyphae thick-walled, aseptate, much branched, with tapering apices, 3–6 μm diam. Cystidia absent. Basidia clavate, 4–sterigmate (up to 3.4 μm), 21–25.7 × 5.6–8 μm, with a basal clamp. Basidiospores cylindric, hyaline, smooth, IKI–, 5.7–6.9 × 2.1–2.3 μm. L = 6.34 μm, W = 2.24 μm, Q = 2.83 (n = 20/1).

Habitat: solitary on dead wood of hardwood or on the ground.

Material examined: KOREA, Gyeonggi-do, Goyang-si, West Five Royal Tombs, on fallen hardwood branch, 13 August 2015, N.G. Kim, J. E. Eom & M. J. So (SFC20150813-58, holotype); KOREA, Gyeongsangbuk-do, Ulleung-gun, Na-ri basin, on fallen hardwood branch, 15 August 1995, Y.W. Lim (SFC19950815-35, paratype); KOREA, Gyeongsangnam-do, Hamyang-gun, Mt. Jiri, on rotten stump of Fraxinus mandshurica, 25 August 2004, J. S. Lee & K. M. Kim (SFC20040825-187, paratype); KOREA, Gyeonggi-do, Uiwang-si, Mt. Cheonggye, on fallen hardwood branch, 20 August 2015, N. G. Kim & H. J. Cho (SFC20150820-61, paratype). GenBank numbers SFC20150813-58 ITS:KY038479. SFC19950815-35 ITS:KY038461. SFC20040825-187 ITS:KY038462. SFC20150820-61 ITS:KY038480.

Notes: This species is often confused with P. melanopus, P. ulleungus and P. varius because of similar basidiocarps and microscopic features; however, the smaller basidiospore of Polyporus koreanus (5.7–6.9 × 2.1–2.3 μm) is distinguishable from P. melanopus (7–9 × 3–3.5 μm), P. ulleungus (6.8–8 × 2.3–3.3 μm) and P. varius (9–12 × 2.5–3 μm) (Gilbertson and Ryvarden 1987).

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 koreanus (SFC20150813-58, holotype). a, b fruiting bodies in the field (SFC20150820-61). c fruiting bodies in the field (SFC20150813-58). d pores of fruiting body (SFC20150813-58). e microscopic structure; basidiospores, basidia, generative hyphae and skeletal-binding hyphae.