Hygrophorus yukishiro N. Endo, R. Tokoo & A. Yamada, in Endo, Tokoo, Fukuda & Yamada, Mycoscience 59 (6): 450 (2018)
Fig. 8
Remark.
The following description is based primarily on Endo et al. (2018), with supplementary data on macro- and micromorphology, habit and distribution from our observations.
Description.
Basidiomata small to medium-sized, fleshy. Pileus 2.5–6 cm diam., convex when young, expanding to broadly convex to plane with age; initially creamy to pale reddish-brown, maturing to brownish-red, darkening when dry, turning light pink after cooking, unchanged when damaged. Lamellae 0.3–0.7 cm wide, subdecurrent, slightly close, with 50–70 full lamellae per pileus; lamellulae numerous, narrowed; off-white to cream-white. Stipe 2.5–5 cm long, 0.8–2 cm diam., central, cylindrical, white; context firm, white. Odour and taste mild.
Basidiospores [40 / 2 / 1] (7.5 –) 8–10 × 5–6.5 (– 7) μm, Q = 1.31–1.67 (– 1.76), Q m = 1.52 ± 0.11, ovoid to ellipsoid, occasionally oblong, smooth, thin-walled, hyaline, inamyloid. Basidia 38–53 (– 64) × 7.5–10 μm, clavate, slender, thin-walled, 4 - sterigmate; sterigmata up to 10 μm long. Hymenophoral trama slightly divergent, non-gelatinised, composed of cylindrical hyphae 3–20 μm diam. and inflated elements up to 32 μm diam., thin-walled, hyaline. Subhymenial layer next to hymenium, not gelatinised, composed of short elements, 12–40 × 3–7 μm, thin-walled, hyaline, cylindrical, irregularly-shaped. Pileipellis an ixotrichoderm, gelatinised, of narrow, closely interwoven hyphae 2–5 μm diam., thin-walled, branched or unbranched. Pileal trama of dense, thin-walled hyphae 4–30 μm diam. Stipitipellis a trichoderm, of hyphae 3–7 μm diam., thin-walled. Stipititrama of parallel, thin-walled, hyphae 4–17 μm diam. Mycelial hyphae 2–5 μm diam., smooth. Clamp connections present in all tissues.
Known distribution.
Anhui, Henan and Zhejiang Provinces, China; Japan.
Habit and habitat.
Gregarious in mixed broadleaf-conifer forests dominated by Quercus, likely associated with Quercus serrata and Q. acutissima; occurs at elevations below 1500 m, fruiting from late winter to spring (February – April).
Material examined.
China • Anhui Province: Chuzhou City (滁州市), elev. 300 m, 5 March 2022, J. Ma 44 (MHKMU MJ-44). Henan Province: Xixia County (西峡县), elev. unknown, 14 March 2021, H. Y. Huang 1011 (MHKMU HHY-1011); • Zhumadian City (驻马店市), elev. unknown, 25 March 2021, H. Y. Huang 1012 (MHKMU HHY-1012). Zhejiang Province: Jinhua City (金华市), elev. unknown, 25 February 2022, H. Y. Huang 1172 (MHKMU HHY-1172).
Notes.
Hygrophorus yukishiro was originally described from Japan and is widely distributed in China (Anhui, Henan and Zhejiang Provinces), where it is also recognised as an edible mushroom (Endo et al. 2018; this study). This species is characterised by a pale reddish-brown to brownish-red pileus, subdistant lamellae (50–70 full lamellae per pileus), ovoid to ellipsoid basidiospores measuring 8–10 × 5–6.5 μm (Q = 1.33–1.67) and a gregarious habit in Quercus - dominated mixed forests at low elevations (<1500 m) during spring (February – April) (Endo et al. 2018; this study).
A Chinese collection from Sichuan Province (voucher SAAS 4870) tentatively identified as H. yukishiro by Wang et al. (2023), exhibits notable morphological and ecological differences. These include a bright coloured (light yellow to orange) pileus, distant lamellae (32–44 full lamellae per pileus), smaller basidiospores (7–8 × 4.5–5 μm, Q = 1.4–1.6) and an autumn fruiting. Together with subtle ITS sequence variation, these features suggest that this specimen may represent a distinct, undescribed species. However, further research and additional collections from the region are necessary to confirm this taxonomic hypothesis.
Publication Date: 2026-06-17