Hydnoporia orienticorrugata M. Cho, Y. Cho, Y. W. Lim & J. J. Kim sp. nov.

Fig. 3

Diagnosis.

Resupinate, effused basidiome, smooth, brown to reddish brown hymenial surface, sterile margin; cylindrical basidia with 10.3–15.9 × 2.8–4.0 μm, sharp-pointed setae with widened basal part and 35.0–64.6 × 8.1–13.2 μm, narrowly cylindrical to allantoid basidiospores with 4.4–5.8 × 1.5–2.0 μm, and growing on an angiosperm branch (a few on gymnosperm branches).

Type.

Korea • Gangwon-do, Pyeongchang-gun, Mt. Heungjeong, 37°65.71'N, 128°32.25'E, alt. 800 m, 30 Oct 2015, Y. W. Lim, (holotype: NIBRFG 0000516804; isotype: SFC 20151030-12) .

Description.

Basidiome resupinate, effused, thin, covering up to 0.1 mm thick. Hymenial surface smooth, membranaceous, crustaceous, with many cracks, brown (7.5 YR, 4 / 2) to reddish brown (5 YR, 5 / 3). Margin sterile, even, concolorous with that of the center. Hyphal system dimitic; generative hyphae septate, branched, without a clamp connection, thick-walled, few thin-walled, hyaline, 2.7–3.5 μm. Skeletal hyphae aseptate, unbranched, without a clamp connection, thick-walled, reddish-yellow (5 YR, 7 / 8) to yellow (10 YR, 7 / 8), 3.4–4.4 μm.

Basidia cylindrical, 4 - spored, smooth, thin-walled, hyaline, 10.3–15.9 (– 16.6) × 2.8–4.0 μm. Setae sharp-pointed, few blunt-pointed, encrusted with crystals, distinctly widened basal part, smooth, bearing narrow lumen, thick-walled, reddish-brown (2.5 YR, 4 / 4), 35.0–64.6 × 8.1–13.2 (– 14.2) μm. Basidiospores narrowly cylindrical to allantoid, smooth, slightly curved, thin-walled, hyaline, with narrow apex, a few bearing oil droplets, 4.4–5.8 (– 6.1) × 1.5–2.0 μm, L = 5.10 μm, W = 1.72 μm, Q = 2.53–3.44, n = 21.

Distribution.

East Asia (Korea, China).

Ecology.

Grew on an angiosperm branch in mixed hardwood forest, although a few grew on gymnosperm branches.

Etymology.

Named after its distribution in East Asian regions and morphological similarity to Hydnoporia corrugata .

Additional specimens examined.

Korea • Gangwon-do, Pyeongchang-gun, Odaesan National Park, 37°44.06'N, 128°35.25'E, alt. 690 m, 19 Oct 2012, Y. Jang & S. Jang, KUC 20121019-16 ; Korea • Gangwon-do, Pyeongchang-gun, Odaesan National Park, 37°44.30'N, 128°35.03'E, alt. 660 m, 23 Nov 2012, Y. Jang & S. Jang, KUC 20121123-05 ; Korea • Gangwon-do, Pyeongchang-gun, Odaesan National Park, 37°44.04'N, 128°35.03'E, alt. 680 m, 01 Oct 2013, Y. Jang & S. Jang, KUC 20131001-21 ; Korea • Gangwon-do, Injae-gun, Mt. Bangtae, 37°87.53'N, 128°31.12'E, alt. 390 m, 12 Feb 2015, Y. W. Lim, SFC 20150212-01 .

Notes.

Our specimens were phylogenetically well grouped with the Chinese specimens (He 761, He 839, and CLZhao 938), which were labeled either as Hymenochaete corrugata, Hymenochaetopsis corrugata, or Pseudochaete corrugata (He and Dai 2012; Yang et al. 2016) (Figs 1, 2). Other than these three specimens and KUC 20121019 -16 from Korea, no other records were found in East Asia, even when the other synonyms of H. corrugata were considered. Nevertheless, the East Asian clade formed a distinct clade from the clade with European Hyd. corrugata, which included the neotype specimen from Norway (O F- 247869). Our findings conform to those of an earlier study, which suggested that sequences identified as Hyd. corrugata in Korea and China could represent a novel species (Miettinen et al. 2019). Hydnoporia orienticorrugata sp. nov. has micromorphological characteristics similar to those of Hyd. corrugata, but the latter has a grey to pale brown hymenial surface (Miettinen et al. 2019) that differs from the new species. Additionally, Hyd. orienticorrugata occurs on angiosperm and gymnosperm branches in Korea and China (He and Dai 2012) whereas H. corrugata occurs only on angiosperm branches and seems to be restricted to Europe (Austria, England, Ireland, Norway, Russia, and Sweden) (Fries 1815; Grundy et al. 2012; Miettinen et al. 2019).