Russula rubiginosus R. Q. Ji, M. L. Xie &amp; J. J. Zhou 2022, sp. nov.
Creators: name: Ji, Rui-Qing
name: Xie, Meng-Le
name: Zhou, Ji-Jiang
name: Meng, Li-Peng
name: Li, Yu
name: Zhang, Zhong-Hui
name: Li, Guo-Jie
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Russulales
Russulaceae
Russula
Russula rubiginosus

description: <i>Russula rubiginosus</i> R. Q. Ji, M.L. Xie &amp; J. J. Zhou, <i>sp. nov.</i>, Figures 3 MycoBank 843715 Diagnosis:— Differs from <i>Russula subrubescens</i> by small-sized basidiospores and large-sized cystidia. Etymology:— Refers to the rusty spots on the cap and stipe of basidiomata. Holotype:— CHINA. Heilongjiang Province: Wudalianchi City, ASL 300 m, 126°11’E, 48°37’N, 13 August 2018, Peng-Jie Xing &amp; Yang Xu (HMJAU58933, GenBank OL828349). Description:— <i>Basidiomata</i> medium-sized. <i>Pileus</i> 40‒72 mm diam., fleshy, firm, first hemispherical, then turned applanate with depressed center after maturation, margin becoming somewhat sulcate with age, glabrous, corinthain pink (xxvii 3ʹʹ d) to livid pink (xxvii 3ʹʹ f) when juvenile, corinthain red (xxvii 3ʹʹ) to corinthain pink (xxvii 3ʹʹd) with age, center orient pink (ii 11 f) to orange pink (ii 9 f) when juvenile, smiona orange (ii 11 b) to orange pink (ii 9 f) with age; mostly more or less covered with small ochraceous tawny (xv 15ʹ i) to mikado brown (xxix 13ʹʹ i) spots. <i>Lamellae</i> adnate, crowded, up to 6 mm wide, more or less furcate towards the stipe, slightly anastomosing, fragile, light ochraceous salmon (xv 13ʹ d) first, primuline yellow (xvi 19ʹ) when mature or dry, often with rust spots at lamellae. <i>Stipe</i> cylindrical to slightly clavate with rounded base, enlarged towards the base, firm, 40‒60 × 8‒13 mm, surface minutely wrinkled, white (liii) when juvenile, becoming baryta yellow (iv 21f) towards the base when old or dry, appearing ochraceous tawny (xv 15ʹ i) to mikado brown (xxix 13ʹʹ i) patches or spots when handled or with age, especially bottom. Context firm, white (liii) when juvenile, naples yellow (xvi 19ʹ d) with age, distinctly yellowing when dry or bruised. <i>Taste</i> acrid. <i>Odor</i> indistinct. <i>Basidiospores</i> (40/2/2) 7–10 (12–) × 6–9 μm, Q = (1.2–)1.3–1.25(–1.31), Q av. = 1.19 ± 0.05, broadly ellipsoid, ornamentation of moderately large and distant: 5–7 (–10) amyloid spines in the circle of diameter of 3 μm on basidiospore surface, spines 1.0–2.0 μm high, mostly isolated, occasionally fused in short chains or crests (0–2 fusions in the circle), line connections very rare and short (0–1 line connection in the circle), not forming a mesh. <i>Basidia</i> (30–) 40–53.7 × (13–) 15–17 (–20) μm, clavate to subclavate, thin-walled, oil granules present when viewed with KOH, 4‒spored, sometimes 2‒spored; sterigmata 6‒8 × 2‒3 µm. <i>Subhymenium</i> pseudoparenchymatic. <i>Lamellar trama</i> mainly composed of large sphaerocytes. <i>Pleurocystidia</i> 66–92 × 9–13 μm, fusiform, clavate to subclavate, often with a subacute tip, thin-walled, sometimes with a small appendage and dense crystal inclusions. <i>Cheilocystidia</i> 60–90 × 8–13 µm, mostly similar to pleurocystidia. <i>Pileipellis</i> is composed of suprapellis and subpellis; suprapellis strongly gelatinized, 140–250 μm thick, composed of dense, ascending or erect hyphal ends and protruding and near surface repent pileocystidia, terminal cells 15–45 × 2–3 μm, cylindrical, often constricted towards the apex; subpellis less gelatinized, 40–100 μm thick, hyphae 2–6 µm wide, dense, strongly intricate, often branched. <i>Pileocystidia</i> numerous and often large sized, narrowly to broadly clavate or fusiform, mainly two or three celled, occasionally one-celled, rarely with more cells, thin-walled, obtuse to subacute, usually inflated near apical part, with terminal cells measuring 30–50 × 6–8 µm, contents in Congo red heteromorphous, usually granulose, but sometimes partly crystalline or banded. <i>Stipitipellis</i> cutis composed of thin-walled, septate, cylindrical, hyaline hyphae 2–4 μm wide, <i>caulocystidia</i> present, dispersed, rare, mainly two or three celled, occasionally one celled, rarely with more cells, thin-walled, obtuse to subacute, usually inflated near apical part, with terminal cells measuring 33–65 × 5–7 μm. <i>Clamp connections</i> absent in all tissues. Habitat and distribution:—Ectomycorrhizal fungi symbiotic with <i>Q. mongolica.</i> Solitary in July to August under <i>Q. mongolica</i> forests. Known from Northeast China. Additional specimens examined:— CHINA. Heilongjiang Province: Wudalianchi City, ASL 300 m, 126°11’E, 48°37’N, 13 August 2018, Peng-Jie Xing &amp; Yang Xu (HMJAU58934, GenBank OL828348). Inner Mongolia Autonomous Region: Zhalantun County, Xiushui Scenic Area, ASL 370 m, 27 July 2013, Sai-Fei Li, Dong Zhao &amp; Guo-Jie Li (HMAS267826, GenBank KX441111); ibid., 28 July 2013, Sai-Fei Li, Dong Zhao &amp; Guo-Jie Li (HMAS267741, GenBank KX441095).
description: Published as part of <i>Ji, Rui-Qing, Xie, Meng-Le, Zhou, Ji-Jiang, Meng, Li-Peng, Li, Yu, Zhang, Zhong-Hui &amp; Li, Guo-Jie, 2022, Russula rubiginosus sp. nov. in Russula subsect. Maculatinae from Heilongjiang Province, Northeast China, pp. 140-148 in Phytotaxa 575 (2)</i> on pages 143-146, DOI: 10.11646/phytotaxa.575.2.3, http://zenodo.org/record/7413193