Russula fanjing Fang Li, 2021

Li, Fang, Li, Guo-Jie, Zhang, Jing, Gao, Huan, Shi, Ru-Shu & Deng, Chun-Ying, 2021, Russula fanjing, a new species of Russula subsect. Russula (Russulaceae, Russulales) from Guizhou province, China, Phytotaxa 480 (2), pp. 139-151 : 142-146

Russula fanjing Fang Li sp. nov., ( Figs. 1–4 )

MycoBank: MB836774

Etymology:— fanjing , the name of the mountain which is the holotype locality.

Holotype:— CHINA Guizhou province, Tongren county, Fanjingshan National Nature Reserve , 108.6572˚ E, 27.9121˚ N, alt. 1948 m, near Quercus trees, 2 August 2020, Fang Li (HGASMF01-10047, ITS: MT 928349 , nrLSU: MW 201672 ).

Diagnosis:—A species with medium-sized basidiocarps, with vivid red, red, pink to pastel red areolate pilei, spores with strongly amyloid warts and ridges interconnected by fine lines in an incomplete or complete reticulum and a suprapellis with short-celled, claw-like branched, lotus-root-like inflated hyphae, and dispersed clavate, septate, pileocystidia.

Description:— Basidiomata medium-sized. Pileus 3–5 cm diam, hemispheric to convex when young, plano-convex to plano-concave at maturity with the center area slightly depressed; surface vivid red (11A8, 9A8), red (11A6–7, 9A6) to pink or pastel red (11A5, 9A5), becoming lighter colored towards margin, areolate, subviscid when moist; margin slightly striate at maturity. Lamellae 3–5 mm wide, white (4A1), not discoloring, adnate, close, occasionally forked near the stipe, intervenose, with 2–3 tiers of lamellulae. Stipe 3–5 × 0.7–1 cm, white (4A1), cylindrical, glabrous or faintly longitudinally ridged, dry, spongy inside. Context 2–3 mm thick in the center of the pileus, white (4A1). Odor absent, taste acrid. Spore print white.

Basidiospores [120/4/3] 6.5–7.0–8 × 5.5–6.0–7 µm, Q = 1–1.15–1.25, Q m = 1.15 ± 0.07, broadly ellipsoid to ellipsoid, occasionally sub-globose, ornamented with large, distant to moderately distant amyloid warts, spines and ridges 0.5–0.8 µm high, occasionally fused in pairs, or triplets, often connected by fine lines in an incomplete to almost complete reticulum, suprahilar plage occasionally amyloid. Basidia 30–41 × 8–12 µm, clavate, 4-spored, sometimes 2-spored, sterigmata 4–8 µm long. Pleurocystidia 33–63 × 6.5–12 µm, moderately numerous to numerous, with the tip projecting slightly beyond the basidia, sub-fusiform, with obtuse, sub-acute to acute apex, with strong refractive content. Cheilocystidia 28–60 × 6.5–10 µm, similar to pleurocystidia in shape and abundance, with less dense content. Marginal cells 8–19 × 4–7 µm, undifferentiated, clavate, cylindrical or irregularly clavate. Lamellar trama composed of hyphae 3–6 µm wide, thin-walled, hyaline, white to yellowish white, divergent and with sphaerocysts 10–50 µm in diam., thin-walled, hyaline. Pileipellis (between the center and margin) well-delimited from the underlying context, two-layered, slightly gelatinous; subpellis ca. 40–100 µm thick, composed of dispersed repent pileocystidia and thinwalled hyphae 3–7 µm wide, with pale red (9A3) to pastel red (9A4) plasmatic pigment, uniformly colored, fading to colorless quickly in 10% KOH, septate, branched, forming a mat close to the underlying trama; suprapellis ca. 30–70 µm thick, a typical trichoderm, composed of dispersed ±erect pileocystidia, and thin-walled hyphae 2–10 µm wide, with pastel red (10A5) to red (10A7) plasmatic pigment, uniformly colored, fading to colorless quickly in 10% KOH, short-celled, claw-like branched and inflated as lotus roots, with end cells 10–25 × 3–9 µm, tapering, bullet-shaped, lageniform, lanceolate, fusiform, subventricose, rarely clavate. Pileocystidia 8–65(122) × 4–12 µm, dispersed in base part of suprapellis and subpellis, bullet-shaped, ovoid, ellipsoid, subventricose, sphaeropedunculate, clavate to long cylindrical, with dense refractive yellowish contents, not septate or septate with 1–4 septa, with a dull lilac (16B3), violet-grey (16F2) to dark violet (16F4) reaction in SV. Acid-resistant incrustations absent. In a same pileus, the structures of the suprapellis in the center and margin are similar to that of between the center and margin; suprapellis in the pileus center with terminal hyphae a little closer and more erect, with end cells 10–25 × 3–8 µm, tapering, bullet-shaped, lageniform, lanceolate, fusiform, subventricose, rarely clavate; suprapellis near the pileus margin with terminal hyphae erect, sub-erect to nearly repent, with end cells 10–24 × 3–9 µm, tapering, bullet-shaped, lageniform, lanceolate, fusiform, subventricose, rarely clavate. Stipitipellis 30–70 µm thick, composed of parallel thin-walled hyphae 5–10 µm wide and with sphaerocysts 15–60 µm in diam., thin-walled, hyaline. Caulocystidia absent. Clamp connections absent in all parts of basidioma.

It is interesting to note that in Russula fanjing the structure of the suprapellis does not change remarkably in the same pileus however, in different basidiomata, the thickness of the suprapellis can be different, and the hyphae in them can be a little different ( Fig. 6A and B ). The thicker the suprapellis ( Fig. 6A ), the longer and a little narrower the terminal hyphae in the suprapellis. When the pileipellis loses its suprapellis, the remaining subpellis is very different: there are no claw-like branched, lotus-roots-like inflated hyphae in the subpellis, the hyphae in it are decumbent or repent, interwoven, tubular elements, and the pileocystidia are decumbent or repent, not vertically to subvertically arranged as they are in suprapellis.

The cellular contents in the cystidia are dense in both pleurocystidia and pileocystidia, and less dense in cheilocystidia. They can be in the form of lumps or crystals. During our examinations, we found that the young pileocystidia (small and non-septate ones) often contained lumpy cellular contents, and crystal cellular contents often appeared in the more mature cystidia.

Habitat and distribution:—Solitary or scattered on soil in forests dominated by Quercus trees, at 1700–2000 m alt.; presently only known from Fanjing Mountain , Guizhou province, China .

Additional specimens examined:— CHINA. Guizhou province, Tongren county, Fanjingshan National Nature Reserve , 108.7031˚ E , 27.9111˚N, alt. 1718 m, near Quercus trees, 3 July 2020, Jing Zhang, Huan Gao (HGASMF01- 10042); ibid, 108.6999˚ E , 27.9081˚N, alt. 1970 m, 3 July 2020, Jing Zhang, Huan Gao (HGASMF01-10043); ibid, 108.7011˚ E , 27.9077˚N, alt. 1950 m, 3 July 2020, Jing Zhang, Huan Gao (Paratype, HGASMF01-9239, ITS: MW 192767 , nrLSU: MW 227645 ) .

Specimens of Russula chiui examined: CHINA. Guizhou province, Tongren county, Fanjingshan National Nature Reserve , 108.7900˚ E , 27.9070˚N, alt. 1979 m, 18 October 2020, Jing Zhang, Huan Gao (HGASMF01-10657, ITS: MW 195051 , nrLSU: MW 227647 ) .

Figures

FIGURE 1. Russula fanjing. A–C: HGASMF01-10047, Holotype, photographer: Fang Li. D–F: HGASMF01-10042, photographer: Jing Zhang & Huan Gao. G: HGASMF01-9239, Paratype, photographer: Jing Zhang & Huan Gao. Scale bars: 1 cm.

FIGURE 2. Microscopic characters of R. fanjing (HGASMF01-10047, holotype). A: Basidiospores. B: Basidia C: Cheilocystidia. D: Pleurocystidia. E: Pileocystidia. F: Pileipellis. Scale bars: A=5µm; B–F=10 µm. Drawings by: Fang Li.

FIGURE 3. Phylogenetic tree of R. fanjing inferred from maximum likelihood (ML) analysis based on ITS sequences of Russula species. ML bootstraps (BS) ≥70%, Bayesian posterior probabilities (PP) ≥0.95 were shown on the branch.

FIGURE 6. Suprapellis between center and margin of the pileus. A: Russula fanjing (HGASMF01-10047, holotype). B: Russula fanjing (HGASMF01-9239, Paratype). C: Russula chiui (HGASMF 01-10657). Scale bars: 10µm. Drawings by: Fang Li.