Russula yanheensis – Facesoffungi number: FoF 2707

Russula yanheensis T.C. Wen, K. Hapuarachchi & K.D. Hyde

Index Fungorum number: IF 552563 Facesoffungi number: FoF: 2707

Etymology: refers to the type collecting site “Yanhe County”, Guizhou Province, China

Holotype: GACP13100308

Basidiocarps small-sized or medium-sized. Pileus 32–70 mm diam., plano-convex, sometimes slightly depressed above the stipe, surface smooth, sticky, broad, fleshy, firm, hemispherical when young, then expanded with depressed centre, depressed weakly in the center when mature, extreme margin becoming somewhat sulcate with age, glabrous, shining. Pileus peeling 1/2 to the disc; margin even, crack when mature. Lamellae regular, adnate, crowded, pale yellowish (2A2), brittle, edge entire. Stipe 23–42 x 13–25 mm, clavate (bottom slightly stigmas), enlarged towards the base, centrally attached, orange white (6A2) when young, pale coralline (9B7) when old, cylindrical to subcylindrical, stuffed, slightly longitudinally wrinkled long and slender, flushed with pink Context
compact, 0.1–1.5 cm thick from stipe top to pileus center, not firm, colour unchanged when bruised. Basidiospores ornamentation amyloid, 5.87–8.26 x 4.88–7.31 um (x = 6.23 x 7.11 um, Q = 1.01–1.32, n = 28), subglobose to spherical, ellipsoid, colourless, without oil droplets, moderately large and distant amyloid warts. Basidia, broadly tapered towards the base, 48.7–77 x 10.3–12.05 um (x = 60 x 11.42 um, Q = 4.32–5.58, n = 10), 4- spored, clavate, hyaline, and smooth. Hymenophoral trama cellular 18.52–33.20 x 16.02–28.58 um (x = 26.82 x 22.28 um, Q = 0.99–1.45, n = 20), subglobose to spherical, ellipsoid, colourless, smooth. Cheilocystidia 73.52–103.79 x 10.29–13.57 um (x = 94.75 x 11.74 um, Q = 6.32 x 11, n = 8), clavate, fusiform to subfusiform, papillae at the top, thin-wall, hyaline, smooth. Pilocystidium rare, emergent, 85.5–113 x 4.1–8.5 um (x = 95.28 x 6.7 um, Q = 10.62–15.94, n = 7) clavate, thin-wall, hyaline, smooth, sometimes with a frayed small appendage and dense crystal inclusions, projecting above the sub hymenium. Pileipellis an ixotrichoderm, composed of 4–6 um thick, cylindrical, rarely swollen hyphae with intracellular reddish pigmentation; terminal cells. Often inflating up to 7–10 (12) um thick and with brownish intracellular pigmentation, some fusiform and with zebroid-encrustations. 19.65–7.87 x 5.92–2.1 um (x = 16.77 x 3.05 um, Q = 2–11.2, n = 9). Stipitipellis a cutis with some hyphal ends ascending; hyphae 4–6 um diam., some hyphae near surface yellowish-white; caulocystidia absent.

Habitat and distribution: On the ground, accompanied in humus rich soil with over heavily rotted litter in forest, mossy temperate mixed coniferous forests, solitary, producing basidiomata from summer to late autumn, only found in “Yanhe County”, Guizhou Province, China.

Material examined: CHINA, Guizhou Province, Coniferous mixed rainforest, 28″N 108 “E, elev. 850 m, 3 October 2013, collector T.C Wen (GACP13100308, holotype). CHINA, Guizhou Province, Coniferous mixed rainforest, 28″N 108 “E, elev. 850 m, 3 October 2013, collector T.C Wen (GACP13100319, paratype). GenBank number ITS:KY195927.

Notes: Russula yanheensis is morphologically and phylogenetically close to Russula pulchra Burl. Russula pulchra has 50–100 mm diameter pileus, stipe 30–70 mm long, ellipsoid basidiospores 6.5–9 × 5.5–7.5 µm; and pilocystidia absent (Binion et al. 2008), but R. yanheensis has 32–70 mm diameter pileus, stipe 23–42 mm long, ellipsoid to subglobose to globose basidiospores 5.8–8.3 × 4.8–7.3 µm, i.e. having smaller pileus, stipe and basidiospores, and the different shapes of basidiospores, presence of pilocystidia. Russula yanheensis is also morphologically similar to R. flavisiccans Bills but the latter species differs from our species by its pileus colour, pilocystidia and cheilocystidia shapes and sizes, further, the stipe never flushes with pink (Kuo and Methven 2014). Further, R. yanheensis is phylogenetically closely related to R. sichuanensis G.J. Li & H.A. Wen, but morphological characteristics are very different from the latter species by its colour, pilocystidia and cheilocystidia shapes and sizes.