Russula pseudosinoparva Zhou & Shen & Hou 2023, sp. nov.
Creators: name: Zhou, Hao
name: Shen, Xiao-Ye
name: Hou, Cheng-Lin
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Russulales
Russulaceae
Russula
Russula pseudosinoparva

description: Russula pseudosinoparva sp. nov. H. Zhou & C. L. Hou (Figs. 3, 4, 5)
MycoBank: MB 847567
Diagnosis:— Russula pseudosinoparva is characterised macroscopically by small basidiomata with a dark red to dark pink pileus; lamellae usually forked near the stipe, with a small number of lamellulae; and microscopically by a suprapellis made up of loose and upright hyphae. Morphologically, R. pseudosinoparva is easily confused with Russula puellaris Fr. (1983: 362). Russula pseudosinoparva differs from R. puellaris by having usually forked lamellae and bigger basidia.
Etymology:—The epithet “ pseudosinoparva ” refers to its related phylogenetic position to Russula sinoparva.
Holotype:— CHINA. Hebei Province, Xinglong County, Wulingshan Mountains National Nature Reserve, 40.272411 N, 117.13521 E, elev. 222 m, 19 August 2019, coll. C. L. Hou, J. Q. Li and G. Q. Cheng (BJTC L131).
Description:— Basidiomata small size. Pileus 10–25 mm diam., initially hemispherical when young, flattened when mature, slightly concave at the center, dry at the edge, slightly viscid in the center, smooth when young, striate when old, cracking near the margin with age, smooth, peeling to 1/3 of the radius, pure red (#e60039) to dark red (#9a0026), central dark pink (#810041) to very dark pink. (#680034). Lamellae white (#ffffff) when young, white (#ffffff) to very pale cream (#ffffd4) when mature, with 9–11 gills per cm of cap circumference, brittle, unequal, usually forked near the margin. Stipe 31–55 × 5–12 mm, white (#ffffff), subcylindrical, smooth, dry, non-brittle, gradually broadening towards base. Pileus context 2–6 mm thick, white (#ffffff) without color change when bruised. Spore print not observed. Taste and smell not observed.
Basidiospores (5.8–)6.8–7.2–7.9(–8.8) × (5.5–)5.9–6.3–6.9(–7.2) μm, [Q = (1.02–)1.06–1.11–1.25(–1.35)], subglobose to broadly ellipsoid, ornamentation consisting of small, moderately distant [(4–)5–7(–8) in a 3 μm diameter circle] amyloid warts, 0.4–1.2 μm high, occasionally to frequently fused in pairs or triplets, short branched chains [(0–)1–3 (–4) in the circle], frequently connected by short or long, fine line connections [(0–) 1–2 in the circle], suprahilar spot large, inamyloid. Basidia (33–)36–39–45(–52) × (11–)13–14–15 (–17) μm, 2–4-spored, clavate, with particles and oil droplets, basidioles clavate or subcylindrical, ca. 7–16 μm wide. Hymenial cystidia on lamellae faces (39–)48–51–63(–70) × (8.1–)8.9–10–12(–14) μm, clavate or fusiform, apically often obtuse or mucronate, sometimes with 2–6-μm-long appendage, contents with refracted inclusions, or some-times with granulose or crystalline, turning ash black (#0d0d0d) in SV. Hymenial cystidia on lamellae edges smaller and narrower to hymenial cystidia on lamellae sides, (23–)27–33–39(–46) × (4.4–)5.4–6.8–10(–12) μm, clavate or subcylindrical, apically often obtuse, sometimes with 2–4 μm long appendage, contents granulose. Pileipellis orthochromatic in Cresyl Blue, sharply delimited from the underlying context, 90–150 μm deep, two-layered. Suprapellis 40–70 μm deep, with strongly gelatinized loose and upright hyphae. Subpellis 50–90 μm deep, composed of horizontally oriented, relatively dense, intricate, 3–8 μm diam hyphae. Hyphal terminations near the pileus margin occasionally branched, sometimes flexuous, thin-walled; terminal cells (10.4–)11–13–19(–22) × (2.8–)3.2–3.8–5.6(–7.1) μm, subcylindrical or clavate, apically mainly obtuse, occasionally attenuated, subterminal cells often wider, ca. 3–6 μm diam, always unbranched. Hyphal terminations near the pileus center similar to those near the pileus margin; terminal cells (14–)15–24(–28) × (2.9–)3.5–6.1(–7.2) μm, subcylindrical or clavate, occasionally ellipsoid, apically obtuse, constricted or attenuated; subterminal cells often wider, ca. 3–8 μm diam, always unbranched. Pileocystidia near the pileus margin mostly 2–4-celled, a few one-celled, terminal cells (10.2–)13–31–44(–75) × (3.8–)4.6–5.9–6.4(–7.1) μm, thin-walled, mainly cylindrical or subcylindrical, occasionally clavate, apically usually obtuse, contents with heteromorphous granulose, turning light ash black (#0d0d0d) in SV. Pileocystidia near the pileus center often smaller, 2–5-celled, thin-walled, terminal cells (13–)17–27–47(–70) × (4.0–)4.5–5.7–6.6(–7.9) μm, mainly clavate or cylindrical, contents granulose or occasionally crystalline. Cystidioid hyphae in subpellis and context with heteromorphous granulose contents, oleiferous hyphae in the subpellis close to the context.
Habitat and distribution:—Solitary and scattered in coniferous forests and mixed coniferous and broad-leaved forests of Pinus tabuliformis Carr. and Juglans mandshurica Maxim, in a warm temperate region of North China (Beijing and Hebei).
Additional specimens examined:— CHINA. Beijing, Pinggu District, Sizuolou Nature Reserve, 40.272411 N, 117.13521 E, elev. 222 m, 19 August 2020, coll. C. L. Hou, G. Q. Cheng and R. T. Zhang (BJTC C381).
description: Published as part of Zhou, Hao, Shen, Xiao-Ye & Hou, Cheng-Lin, 2023, A new species of Russula subgenus Russula (Russulaceae, Russulales) from Yanshan Mountains, North China, pp. 195-208 in Phytotaxa 609 (3) on pages 202-204, DOI: 10.11646/phytotaxa.609.3.3, http://zenodo.org/record/8281343