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

Index Fungorum number: IF552514 Facesoffungi number: FoF 2632

Etymology: referring to the similar species to P. varius, but with Far East Asian distribution.

Holotype: SFC20130704-20

Basidiocarps annual, central to laterally stipitate; Pileus circular to dimidiate, plane then funnel-shaped, up to 70 mm diam., 2.5 mm thick; pileal surface cream 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 mm thick. Tube continuous with the context, up to 1.5 mm thick. Stipe central, brown to dark brownish-black, longitudinally wrinkled, apex distinct from the pore, up to 20 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, 21–25 × 5.7–8 μm, with a basal clamp. Basidiospores cylindric, hyaline, smooth, IKI-, 5.1–6.8 × 2.3–2.5 μm. L = 5.7 μm, W = 2.4 μm, Q = 2.4 (n = 20/1).

Habitat: solitary to gregarious on dead wood of hardwood.

Material examined: KOREA, Gyeongsangbuk-do, Yecheon-gun, Mt. Hagga, on fallen hardwood branch, 4 July 2013, Y.W. Lim (SFC20130704-20, holotype); ibid. (SFC20130704-06, paratype); KOREA, Gyeongsangbuk-do, Sangju-si, Seongjubong Natural Recreation Forest, on fallen hardwood branch, 9 August 2013, H. Lee, W. J. Kim & S-Y. Oh (SFC20130809-44, paratype); KOREA, Jeju-do, Seogwipo-si, Hannam Experimental Forest, on rotten hardwood stump, 7 August 2012, Y. W. Lim, H. Lee, W. J. Kim & J. S. Gyeong (SFC20120807-12, paratype); KOREA, Chungcheongnam-do, Boryeong-si, Seongjusan Natural Recreation Forest, on fallen hardwood branch, 21 August 2012, Y. W. Lim, H. Lee, W. J. Kim & Y. J. Min (SFC20120821-36, paratype); ibid. (SFC20120821-59, paratype); KOREA, Jeollabuk-do, Namwon-si, Mt. Jiri, on fallen hardwood branch, 20 July 2005, H. S. Jung (SFC20050720-60, paratype); ibid., 22 July 2004, J. S. Lee & S. H. Hong (SFC20040722-26, paratype). GenBank numbers SFC20130704-20 ITS:KY038470. SFC20130704-06 ITS:KY038469. SFC20130809-44 ITS:KY038475. SFC20120807-12 ITS:KY038465). SFC20120821-36 ITS: KY038468. SFC20050720–60 ITS:KY038463.

Notes: This species has variable basidiocarp shapes similar to Polyporus varius. Therefore, many of specimens in Korea had been misidentified as Polyporus varius. Two types of P. varius sequences were reported in a previous study (Sotome et al. 2008). The first included sequences from the U.S., Russia, and Japan (Sotome et al. 2011; Dai et al. 2014) and the second was unique to Japan (AB587635, Sotome et al. 2011). Phylogenetic analysis based on ITS sequences showed that P. orientivarius formed a monophyletic group with the second type of P. varius sequence and was distantly related to P. varius. In addition, P. varius has smaller pores (7–9 mm) and longer basidiospores (9–12 × 2.5–3 μm) (Gilbertson and Ryvarden 1987) than those of P. orientivarius. Therefore, both morphological and molecular evidence support P. orientivarius as a new species that is clearly separate from P. varius.

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 orientivarius (SFC20130704-20, holotype). a fruiting bodies in the field (SFC20120807-12). b fruiting bodies in the field (SFC20130704-20). c pores of fruiting body (SFC20130704-20). e microscopic structure; basidiospores, basidia, generative hyphae and skeletal-binding hyphae.