Cortinarius neocaninus M. L. Xie, T. Z. Wei, Y. Li & Dima 2025, sp. nov.

Cortinarius neocaninus M.L. Xie, T.Z. Wei, Y. Li & Dima, sp. nov. MB 843749. Figs 3D, E, 6J, 7J. Etymology: The name refers to the affinity with Cortinarius caninus. Typus: China, Inner Mongolia Autonomous Region, Genhe County, Mangui Town, in mixed forest of Larix gmelinii and Betula platyphylla, alt. 630 m, 10 Sep. 2019, M.L. Xie (holotype HMJAU 48691). Pileus 15–52 mm diam., hemispherical at first, later plane to convex with a broadly umbonate, surface somewhat viscid when moist, not hygrophanous, with yellowish fibrillose, at first olive brown, then greyish orange to brownish orange, dull. Lamellae subadnate at first, then emarginate, moderately crowded, violaceous white when young, later greyish orange to brown, edges paler, somewhat uneven. Stipe 60–90 mm long, 3–6 mm thick, cylindrical to subcylindical, somewhat thickened at the base (up to 13 mm), surface white fibrillose, later yellowish, bluish tinges at the apex, basal mycelium whitish. Universal veil yellowish. Context fleshy, hygrophanous when moist, hollow in stipe, in pileus and in stipe violet tinge at first, especially at the stipe apex, later becoming white. Odour weak. Taste mild. Basidiospores 7.2–10.6 × 5.8–7.7 μm, Q = 1.07–1.59, Xav. = 7.9–8.9 × 6.5–6.8 μm, Qav. = 1.21–1.4, subgloboid, broadly ellipsoid to ellipsoid, moderately and densely verrucose. Basidia clavate, 4-spored, hyaline to subhyaline, rarely yellowish to yellowish brown. Lamellar edge fertile. Pileipellis duplex: epicutis thinly developed, hyphae slightly interwoven, hyaline to yellowish brown, 3–13 μm wide, smooth to slightly encrusted; hypocutis well developed, hyphae 8–20 μm wide, hyaline to slightly yellowish brown, somewhat irregular. Clamp connections present. Ecology and distribution: Known from Heilongjiang and Inner Mongolia of China in Larix gmelinii forests or mixed Betula platyphylla, and known from Sichuan in mixed forests of Abies and Quercus, Xinjiang in Abies or Picea forests. Also known from Estonia based on molecular data. Additional specimens examined: China, Heilongjiang Province, Mohe County, Jingou Forest Farm, in mixed forest of Larix gmelinii and Betula platyphylla, alt. 730 m, 26 Aug. 2016, M.L. Xie, HMJAU 48688; in Larix gmelinii forest, alt. 500 m, 19 Aug. 2017, M.L. Xie, HMJAU 44495; Inner Mongolia Autonomous Region, Genhe County, ManGui Town, in mixed forest of Larix gmelinii and Betula platyphylla, alt. 630 m, 10 Sep. 2019, M.L. Xie, HMJAU 48690; Sichuan Province, Xiaojin County, Heshangcun Songrong Protected Area, in mixed forest of Abies and Quercus, alt. 3578 m, 18 Aug. 2015, T.Z. Wei & D. Wang, HMAS 274431; Xinjiang Uygur Autonomous Region, Hami City, Haiziyan Town, in Abies forest, alt. 2500 m, 3 Aug. 2019, M.L. Xie & P.S. Jia, HMJAU 48689; Ili Kazak Autonomous Prefecture, Qiaoerma, in Picea forest with shrubs, alt. 2341 m, 13 Aug. 2015, T.Z. Wei & K. Wang, HMAS 274789. Additional nrITS sequences data from public sequence repositories: Estonia, UDB0168416, S594 from soil, as Cortinarius sp. in UNITE; UDB0176168, S682 from soil, as Cortinarius sp. in UNITE; UDB0180344, S703 from soil, as Cortinarius sp. in UNITE; UDB0513824, G4278 from soil, as Cortinarius sp. in UNITE; Saare maakond, Leisi vald, UDB034762, TAAM128969 as Cortinarius sp. in UNITE. Notes: Cortinarius neocaninus has small-sized basidiomata without bluish tinges except for the lamellae and stipe apex. The pileus is olive brown at first, and then brownish orange, the context is somewhat hollow at the stipe, and the basidiospores are subglobose to ellipsoid. The nrITS sequences of C. neocaninus differ from those of the North American C. anomalodelicatus by only three to four substitutions and indel positions. The former, however, forms a well-supported monophyletic group in both ML and BI analyses. It is also related to C. caninus, which is one of the typically medium- to large-sized and robust species in sect. Anomali (Dima et al. 2016).