Hydnoporia rimosa (Lloyd) Spirin & Miettinen, Fungal Systematics and Evolution 4: 92 (2019)

Fig. 5

Diagnosis.

Resupinate, effused basidiome, reddish brown hymenial surface, white to brown margin; cylindrical to narrowly clavate basidia with 10.0–14.1 × 2.7–3.4 μm, sharp to blunt pointed setae with 44.4–83.1 × 8.2–13.4 μm, narrowly cylindrical to allantoid basidiospores with 4.7–6.1 × 1.7–2.0 μm, and occurs on angiosperm branches.

Type.

Japan • Tohoku, Sendai, 24 Oct 1920, Yasuda, (holotype: TNS -F 203210; lectotype: MBT 387146) .

Description.

Basidiome resupinate, effused, thin, leathery, up to 0.2 mm thick. Hymenial surface smooth, membranaceous, crustaceous, with many cracks, light reddish-brown (2.5 YR, 6 / 4) to reddish-brown (2.5 YR, 5 / 3). Margin sterile, even, edge whitish (7.5 YR, 9 / 2) when fresh and becomes brown (7.5 YR, 5 / 8). Hyphal system dimitic; generative hyphae septate, branched, without a clamp connection, thick-walled, hyaline to pale brown (10 YR, 6 / 3), 3.0–3.5 μm. Skeletal hyphae aseptate, unbranched, without a clamp connection, thick-walled, yellowish (7.5 YR, 6 / 8) to reddish brown (2.5 YR, 4 / 3), 3.5–4.2 μm.

Basidia cylindrical to narrowly clavate, 4 - spored, smooth, thin-walled, hyaline, 10.0–14.1 (– 14.5) × 2.7–3.4 μm. Setae sharp- to blunt-pointed, encrusted with crystals, smooth, bearing a wide or narrow lumen, thick-walled, projecting up to 15 µm above the hymenium, dark reddish brown (2.5 YR, 2.5 / 3), 44.4–83.1 × 8.2–13.4 (– 18.6) μm. Basidiospores narrowly cylindrical to allantoid, smooth, thin-walled, hyaline, with narrow apex, 4.7–6.1 × (1.5 –) 1.7–2.0 μm, L = 5.40 μm, W = 1.80 μm, Q = 2.64–3.30, n = 20.

Specimen examined.

Korea • Gangwon-do, Pyeongchang-gun, Odaesan National Park, 37°44.30'N, 128°35.01'E, alt. 660 m, 9 Nov 2012, Y. Jang & S. Jang, KUC 20121109-19 .

Notes.

The observed Hyd. rimosa specimen from Korea has similar morphological characteristics as those of the type specimen (TNS - F 203210), but the type specimen has abundant blunt-pointed setae and wider basidiospores (L = 5.22, W = 1.99, Q = 2.47–2.78) (Miettinen et al. 2019) compared to the Korean specimen. In the phylogenetic tree, Hyd. diffissa is closely related to Hyd. rimosa . These two species are practically indistinguishable in morphology, except that Hyd. rimosa has a wider lumen and greater size variation of setae (Miettinen et al. 2019). However, they are geographically distinct, where Hyd. diffissa is distributed across North and South America (Colombia, Peru, and Eastern US) (Miettinen et al. 2019), while Hyd. rimosa is distributed in East Asia (Japan, Korea, and Far East Russia) (Ito 1930 b; Miettinen et al. 2019).