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

Index Fungorum number: IF552513 Facesoffungi number: FoF 2631

Etymology: referring to the characteristic short basidia.

Holotype: SFC20130808-24

Basidiocarps annual, central stipitate; Pileus circular, plane then funnel-shaped, up to 30 mm diam., 1.5 mm thick; pileal surface light buff in the center, brown near margin, fibrillose with flattened, radially striate, glabrous, margin reddish-black, undulate, enrolled. Hymonophore white, cream to brown; pores fine, rounded to angular, 8–9 per mm. Context in pileus pale buff, corky, up to 1 mm thick. Tube continuous with the context, up to 0.5 mm thick. Stipe central, brown to dark brown, smooth to longitudinally wrinkled, apex distinct from the pore, up to 40 mm long and 2 mm thick. Hyphal system dimitic; generative hyphae hyaline in KOH, thin-walled, 2.5–3 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 2.3 μm), 15–16.6 × 6.3–7.4 μm, with a basal clamp. Basidiospores cylindric, hyaline, smooth, IKI–, 6.3–7.4 × 2.8–3.3 μm. L = 6.77 μm, W = 2.86 μm, Q = 2.37 (n = 20/1).

Habitat: solitary to gregarious on dead wood of hardwood.

Material examined: KOREA, Gyeongsangbuk-do, Sangju-si, Mt. Noem, on fallen hardwood branch, 8 August 2013, H. Lee, W. J. Kim & S-Y. Oh (SFC20130808-24, holotype). KOREA, Gangwon-do, Inje-gun, Baekdam temple, on fallen hardwood branch, 9 July 1999, Y. W. Lim (SFC19990709-26, paratype). GenBank number ITS:KY038474.

Notes: This species shares similar characteristics with many Polyporus species including eccentric stipe, thin pileus, and small pores. Although the smaller pileus (less than 3 cm), pores (8–9 mm) and basidia (15–16.6 × 6.3–7.4 μm) of P. brevibasidiosus are distinguishable characters, morphologyalone is not sufficient for species level identification. ITS sequence analysis is useful to confirm its identity and phylogenetic position.

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 brevibasidiosus (SFC20130808-24, holotype). a, b fruiting bodies (SFC20130808-24). c fruiting bodies in the field (SFC20130808-24). d pores of fruiting body (SFC20130808-24). e microscopic structure; basidiospores, basidia, generative hyphae and skeletal-binding hyphae.