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

Index Fungorum number: IF552512 Facesoffungi number: FoF 2630

Etymology: referring to similar morphology and close phylogenetic relationship with P. dictyopus.

Holotype: SFC20130719-53

Basidiocarps annual, central to laterally stipitate; Pileus circular to dimidiate, plane then funnel-shaped, up to 60 mm diam., 2.5 mm thick; pileal surface whitish when juvenile to pale buff, brown and dark brown with age, fibrillose with flattened, radially striate, slightly glabrous, margin ochreous, sharp and undulate. Hymonophore white, cream, buff to brown; pores fine, rounded to angular, 8–10 per mm. Context in pileus pale buff, corky, up to 2 mm thick. Tube continuous with the context, up to 0.5 mm thick. Stipe central, brown to dark brownish-black, smooth to longitudinally wrinkled, apex distinct from the pore, pores traces observed at upper portion of blackish stipe, up to 15 mm long and 6 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, 3–5 μm diam. Cystidia absent. Basidia clavate, 4–sterigmate (up to 7.9 μm), 21–23 × 5.1–6.9 μm, with a basal clamp. Basidiospores cylindric, hyaline, clear one or two oil drops, smooth, IKI–, 6.8–9.1 × 2.2–2.8 μm. L = 7.39 μm, W = 2.34 μm, Q = 3.16 (n = 20/2).

Habitat: solitary to gregarious or frequently concrescent on dead wood of hardwood, occasionally on conifer (SFC20110818–02).

Material examined: KOREA, Gyeongsangbuk-do, Sangju-si, Mt. Noem, on fallen hardwood branch, 19 July 2013, H. Lee, W. J. Kim & Y. J. Min (SFC20130719-53, holotype); KOREA, Gangwon-do, Wonju-si, Mt. Chiak, on dead conifer, 18 August 2011, Y.W. Lim (SFC20110818-02, paratype); KOREA, Gyeongsangbuk-do, Yecheon-gun, Mt. Hagga, on fallen hardwood branch, 4 July 2013, Y.W. Lim (SFC20130704-39, paratype); KOREA, Jeollabuk-do, Jinan-gun, Unjangsan Natural Recreation Forest, on fallen hardwood branch, 23 July 2014, J. Y. Park, H. Lee & H. J. Cho (SFC20140723-08, paratype); KOREA, Jeju-do, Jeju-si, Bijarim, on fallen hardwood branch, 30 June 2015, Y. W. Lim, N. G. Kim & H. Lee (SFC20150630-48, paratype); KOREA, Chungcheongbuk-do, Boeun-gun, Mt. Songni, on dead trunk of oak, 25 July 2015, H. Lee (SFC20150725-05, paratype). GenBank numbers SFC20130719-53 ITS:KY038473. SFC20110818-02 ITS:KY038464. SFC20130704-39 ITS:KY038471. SFC20140723-08 ITS:KY038476. SFC20150630-48 ITS:KY038477. SFC20150725-05 ITS:KY038478).

Notes: Basidiocarps of this species are most similar to those of P. badius. P. badius is easily distinguished by its lack of clamp connection. In a phylogenetic analysis, P. badius formed a separate clade within the Melanopus clade, but P. subdictyopus is located in a sister clade together with P. dictyopus. Basidiocarps shape and microscopic features of P. dictyopus are hard to distinguish except its pantropical distribution. One or two oil drops in the basidiospores of P. subdictyopus differentiate it from P. dictyopus.

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 subdictyopus (SFC20130719-53, holotype). a fruiting bodies in the field (SFC20110818-02). b fruiting bodies in the field (SFC20130704-39). d pores of fruiting body (SFC20140723-08). e microscopic structure; basidiospores, basidia, generative hyphae and skeletal-binding hyphae.