Russula wulingshanensis C.L.Hou, H.Zhou, & G.Q.Cheng sp. nov.

MycoBank: MB844537

Figs 5–6

Diagnosis

Russula wulingshanensis sp. nov. differs from other species by the purple pinkish, pale brown or greyish white pileus disc with grey-white to grey-purple margin at maturity, small basidiospores (5.8–6.3– 6.8 ×4.9–5.2–5.5), pleurocystidia turning pink in sulfovanillin and a separate phylogenetic position.

Etymology

The epithet ʻ wulingshanensis ʼ refers to the locality where the type specimen was collected.

Material examined

Holotype CHINA • Hebei Province, Xinglong County, Wulingshan Mountain National Nature Reserve; 40°33′40.7″ N, 117°28′44.9″ E; elev. 1248 m; in broadleaf forest dominated by Betula dahurica Pall.; 23 Aug. 2020; C.L. Hou & G.Q. Cheng; BJTC[BJTC C403].

Additional material

CHINA • Hebei Province, Xinglong County, Wulingshan Mountain National Nature Reserve; 40°33′39.7″ N, 117°28′44.7″ E; elev. 1248 m; in broadleaf forest dominated by Betula dahurica; 19 Aug. 2019; H. Zhao & J.Q. Li; BJTC[BJTC L278] • ibid.; 40°33′40.1″ N, 117°28′44.7″ E; elev. 1256 m; in broadleaf forest dominated by B. dahurica; 23 Aug. 2020; C.L. Hou, G.Q. Cheng & R.T. Zhang; BJTC[BJTC C399].

Description

Basidiomata small to medium-sized. Pileus 14–63 mm in diam., hemispheric at first, applanate with a depressed centre to infundibuliform at maturity, margin smooth when young, often fine striate at maturity, cuticle peeling often one-fifth of the pileus radius; purple pinkish (#ff989b), pale brown (#a95b4c) or greyish white (#ececea), margin grey-white (#e9e9e6), grey-purple (#aaaad5). Lamellae white (#fffff) to pale yellow (#ffffcc), adnate, fragile, up to 6 mm wide, approximately 10–12 pieces per cm near the pileus margin, lamellulae absent, usually forked near the stipe. Stipe 72–105 × 12–27 mm, solid, subcylindrical to slightly inflated at the base, sometimes light brown to brownish orange (#ae6020) when bruised. Context unchanging when bruised, odour unpleasant, taste mild. Spore print not observed.

Basidiospores (5.5–)5.8–6.3–6.8(–7.3) × (4.7–)4.9–5.2–5.5(–5.6) μm, Q=(1.02–)1.10–1.21–1.32(–1.45), subglobose to ellipsoid, ornamented with small and amyloid warts of height 0.2–0.9 μm; hilar appendix small, amyloid or weakly amyloid. Basidia (31–)35–40–45(–48) × (8.5–)9.4–11–12(–15) μm, 2- and 4-spored, clavate and slightly inflated in the upper half, thin-walled, with guttate or granular contents, sterigmata 4.3–5.8 × 0.9–1.2 μm; basidiola clavate or subcylindrical, 7–11 μm wide. Pleurocystidia dispersed, (48–)58–71–84(–95) × (8.6–)9.7–11–12(–14) μm, clavate, fusiform, subcylindrical sometimes lanceolate, apically always obtuse, few mucronate, sometimes with a 2–7 μm long appendage, thinwalled, contents granulose, heteromorphous-crystalline, pink in sulfovanillin. Cheilocystidia (33–)40– 51–62(–67) × (6.2–)8.1–9.1–10(–11) μm, clavate and subfusiform, apically always obtuse, sometimes with 3–12 μm long appendage; contents granulose, heteromorphous-crystalline, often dispersed in the upper and middle layers. Marginal cells (20–)22–24–26(–29) × (4.9–)5.6–6.7–7.8(–9.4) μm, clavate or subfusiform, sometimes fusiform. Pileipellis orthochromatic in cresyl blue, sharply delimited from the underlying context, 120–180 μm thick, two-layered, strongly gelatinized, suprapellis 50–80 μm thick, composed of ascending to erect hyphal terminations; subpellis 70–100 μm thick, composed of horizontally oriented, interwoven hyphae. Hyphal terminations near the pileus margin intricate and sometimes branched, occasionally flexuous, thin-walled; terminal cells (11–)15–21–27(–31) × (3.0–)3.3–4.1–4.9(–5.9) μm, mostly subcylindrical, occasionally subfusiform or lageniform, apically usually obtuse, sometimes attenuated or constricted, subterminal cells frequently shorter and slightly inflated, ca 4–7 μm wide, rarely branched. Hyphal terminations near the pileus centre similar to those near the pileus margin; terminal cells (12–)18–26–35(–44) × (2.1–)3.5–4.4–5.3(–6.2) μm, subcylindrical, subfusiform or lageniform, apically usually obtuse, sometimes attenuated or constricted, subterminal cells frequently short, 2–6 μm wide, rarely branched. Pileocystidia near the pileus margin (35–)39–50–62(–68) × (5.0–)5.2–5.8–6.4(–7.5) μm, thin-walled, cylindrical, clavate or subfusiform, apically usually obtuse, sometimes with a 2–5 μm long appendage, contents heteromorphous-granulose, black in sulfovanillin. Pileocystidia near the pileus centre (32–)41–50–59(–71) × (4.3–)4.7–5.8–6.9(–8.9) μm, thin-walled, apically usually obtuse, sometimes with 1–4 μm long appendage, contents with granulose or heteromorphous-crystalline, black in sulfovanillin. Cystidioid hyphae dispersed in subpellis and context, with heteromorphous-granulose contents, oleiferous hyphae frequent in subpellis and context.