Russula subpallescens J. Q. Yan, B. J. Zhong & S. N. Wang sp. nov.
Fig. 3
Diagnosis.
Russula subpallescens is mainly characterised by its medium-sized basidiomata, a pinkish-white pileus, adnate, unforked, and crowded lamellae of equal length with 10–13 per cm at the margin and intervenose veins, and a white stipe that develops pale yellow to maize yellow patches when old or bruised for a long time; basidiospores with ornamentation composed of dispersed warts, frequently connected by short lines, nearly subreticulate, subcylindrical to fusiform hymenial cystidia with obtuse or acute apices and frequent papillae, and cylindrical pileocystidia with obtuse or attenuated apices and papillae.
Holotype.
China • Hubei Province, Yichang City, Xingshan County, Longdongpo, 31°23'47"N, 110°55'48"E, alt. 1526 m, 24 Jul 2024, Jun-Qing Yan, Lin-Gen Chen, Hong Chen, Ling Ding (HFJAU 5665).
Etymology.
‘ subpallescens’ refers to its morphology similar to ‘ Russula pallescens ’.
Chinese name.
近粉白红菇.
Description.
Basidiomata medium-sized. Pileus ca. 55 mm in diameter, shallowly infundibuliform; surface smooth, dry, glabrous, pinkish-white (10 A 2). Lamellae 2.0– 3.5 mm wide, adnate, without furcations, equal in length, crowded, 10–13 per cm near pileus margin, with intervenose veins, white (1 A 1). Stipe ca. 41 × 15 mm, cylindrical, central, white (1 A 1), hollow, but developing pale yellow (4 A 4) to maize yellow (4 B 5) patches when old or long after being bruised. Context thick, white (1 A 1), unchanging when bruised; taste and odour not recorded.
Basidiospores (6.7 –) 6.9–7.9 (– 8.4) × (5.8 –) 5.9–6.7 (– 6.8) μm, Q = (1.03 –) 1.11–1.26 (– 1.32), globose, subglobose, broadly ellipsoid or ellipsoid; ornamentation composed of many dispersed, obtuse-conical to subcylindrical amyloid warts, moderately dense (3–7 in a 3 μm diam. circle), frequently connected by short lines, nearly subreticulate, 0.3–0.8 μm high; suprahilar plage inamyloid. Basidia 39.5–52.0 × 8.5–11.5 μm, clavate, 2 - or 4 - spored. Hymenial cystidia on lamellae sides 50.5–74.0 × 7.0–11.5 μm, subcylindrical or fusiform, apically obtuse or acute, often with a papilla, thin-walled, contents granulose, turning greyish-black in sulphovanillin. Hymenial cystidia on lamellae edges 53.0–66.5 × 5.0–9.0 μm, subcylindrical or fusiform, apically obtuse or acute, often with a papilla, contents granulose, turning greyish-black in sulphovanillin. Pileipellis metachromatic in cresyl blue, indistinctly two-layered, ca. 120–250 μm thick; suprapellis 60–90 μm deep, composed of erect or ascending hyphae that are attenuated at the apex; subpellis 60–150 μm deep, composed of interwoven hyphae. Hyphal terminations near the pileus margin thin-walled, occasionally flexuous; terminal cells 11.0–28.0 × 2.5–5.0 μm, cylindrical, apically attenuated or obtuse. Hyphal terminations near the pileus centre similar to those near the margin; terminal cells 9.5–24.5 × 2.5–4.5 μm, cylindrical, apically attenuated or obtuse. Pileocystidia near the pileus margin 20.0–56.5 × 4.0–6.0 μm, cylindrical, apically obtuse or attenuated, with a papilla, thin-walled; contents granular, turning greyish-black in sulphovanillin. Pileocystidia near the pileus centre 17.0–44.5 × 3.5–5.0 μm, cylindrical, apically obtuse or attenuated, with a papilla, thin-walled; contents granular, turning greyish-black in sulphovanillin. Cystidioid hyphae in pileipellis and context with heteromorphous contents; oleiferous hyphae in subpellis with refractive contents.
Habitat.
Mixed coniferous and broad-leaved forest dominated by Cupressaceae, Pinaceae, Theaceae, and Fagaceae.
Notes.
Based on the medium-sized basidiomata, pinkish-white pileus, basidiospores with an inamyloid suprahilar plage, metachromatic reaction of the pileipellis in cresyl blue, and unicellular pileocystidia, this species can be classified into Russula subg. Heterophyllidiae subsect. Cyanoxanthinae. Within this section, R. subpallescens shares ITS sequence similarities in the range of 97 % – 98 % with R. cyanoxantha (Schaeff.) Fr., R. nigrovirens Q. Zhao, Y. K. Li & J. F. Liang, and R. perviridis Y. L. Chen, B. Chen & J. F. Liang. However, R. cyanoxantha has spore ornamentation composed of isolated warts without connecting lines and longer pleurocystidia (up to 100 µm) (Bon 1988; Sarnari 1998). Russula nigrovirens has a greenish-white to greyish-green pileus with patches, rare lamellae furcations only near the stipe, and shorter cheilocystidia (46.0–55.0 µm) (Zhao et al. 2015). Russula perviridis differs by having a greyish-green to dark green pileus (sometimes tinged yellowish-brown), reticulate spore ornamentation, and frequently forked lamellae (Chen et al. 2024 a).
Morphologically, R. subpallidirosea J. B. Zhang & L. H. Qiu, R. vesca Fr., and R. galochroa (Fr.) Fr. are quite similar to this species, as all share white to pinkish pileus tones, white stipe with yellow to brown spots, and basidiospores ranging from 6.5–8.5 × 5.5–7.0 μm. However, R. subpallidirosea can be distinguished by its frequently forked lamellae, relatively lower spore ornamentation (<0.6 μm), and shorter pleurocystidia (35–50 × 5–8 μm) (Zhang et al. 2017). Russula vesca has spore ornamentation composed of isolated warts with a lower height (<0.5 μm) and lacks pileocystidia (Sarnari 1998). Russula galochroa features extremely low spore ornamentation (0.1–0.2 μm) that is completely isolated without any connections (Knudsen and Vesterholt 2012).
Publication Date: 2026-06-23