Cortinarius albocyaneus Fr., Monogr. Hymenomyc. Suec.

Xie, M. L., Dima, B., Wang, K., Phukhamsakda, C., Li, Y., Qi, L. L., Li, G. J., Liu, T. Z., Jia, P. S., Wang, Q., Song, L. R., Wei, T. Z. & Li, Y., 2025, Taxonomy and phylogeny of Cortinarius sect. Anomali in China, Persoonia 54 (1), pp. 225-263 : 243-244

Cortinarius albocyaneus Fr., Monogr. Hymenomyc. Suec. (Upsaliae) 2: 62. 1863. Figs 2B , 6B , 7B .

Pileus 37–65 mm diam., sometimes up to 100 mm, at first convex, later plane to plano-convex, margin persistently incurved, surface somewhat viscid and weakly hygrophanous when young or moist, somewhat shiny to distinctly glittery when dry, at first with veil remnants, especially at the margin, smooth when mature, light blue to greyish blue when young, finally slightly greyish ochraceous to greyish brown, rarely entirely light blue even when old. Lamellae subadnate at first, then emarginate, moderately crowded, greyish violet when young, later greyish ochraceous to brown, edges paler, uneven. Stipe 45–100 mm long, 4–10 mm thick, cylindrical to clavate, slightly thickened at the base, surface shiny white fibrillose, at first pale violet, later becoming bluish tinged at apex, yellowish to brownish downwards, basal mycelium whitish, sometimes with bluish tinges. Universal veil sparse, bluish white, forming fibrils on pileus surface and sock like sheath on the stipe, later becoming yellowish. Context rather thin, hygrophanous when moist, stipe sometimes hollow, at first bluish white at the pileus and upper part of the stipe, yellowish below, later becoming yellowish. Odour somewhat radish. Taste mild. Basidiospores (6.0–)7.6–8.9 × (4.6–)5.8– 7.2 μm, Q = 1.14–1.32, Xav. = 8.1 × 6.7 μm, Qav. = 1.21– 1.24, subgloboid to broadly ellipsoid, moderately verrucose, indextrinoid. Basidia clavate, 4-spored, hyaline to subhyaline, rarely yellowish to yellowish brown. Lamellar edge fertile. Pileipellis duplex: epicutis well developed, hyphae upward loosely entangled, hyaline or yellowish brown, 3–7 μm wide, smooth or weakly encrusted; hypocutis well developed, hyphae 7–22 μm wide, hyaline or slightly yellowish brown, enlarged, almost isodiametric, somewhat irregular. Clamp connections present.

Ecology and distribution: Solitary or gregarious under deciduous forests of Betula and/or Quercus , also in mixed forests of Betula and Pinaceae ( Abies , Larix and/or Pinus ). Known from Beijing, Hebei, Heilongjiang, Inner Mongolia, Jilin, and Sichuan of China. Widespread in Europe, North America and Siberia of Russia as well.

Specimens examined: China, Beijing Municipality, Fangshan District, Baihuashan National Nature Reserve, in Betula albosinensis forest, alt. 1850–1970 m, 25 Aug. 2020, K. Wang, HMAS 291443, HMAS 291444, HMAS 291446, T.Z. Wei, HMAS 295967; Hebei Province, Laiyuan County, Baishishan Geopark, in Betula albosinensis forest, alt. 1900 m, 21 Aug. 2019, M.L. Xie, HMJAU 48707, HMJAU 48708, HMJAU 48712; 21 Aug. 2020, Y.B. Guo, HMAS 291406; 25 Aug. 2020, T.T. Fan, HMAS 291371, HMAS 291374, X.N. Shan, HMAS 291360; Heilongjiang Province, Dongning County, alt. 415 m, 5 Sep. 2009, T.Z. Wei, HMAS 260342; Inner Mongolia Autonomous Region, Genhe County, Mangui Town, Ningcuishan Park, in mixed forest of Larix gmelinii and Betula platyphylla , alt. 820 m, 25 Aug. 2017, M.L. Xie, HMJAU 44483; Arxan County, in Betula platyphylla forest, alt. 1200 m, 22 Aug. 2018, M.L. Xie, HMJAU 44498, HMJAU 44499, HMJAU 44500; Kalaqin Qi, Ma’anshan National Forest Park, 2 Sep. 2019, T.Z. Liu & Y.M. Gao, CFSZ 21464; Ningcheng County, Heilihe National Nature Reserve, Dabagou, 29 Aug. 2019, T.Z. Liu & Wulantuya, CFSZ 21343; Jilin Province, Antu County, Changbai Mountain National Nature Reserve, in Betula platyphylla forest, alt. 1100 m, 6 Sep. 2018, M.L. Xie, HMJAU 44501; 19 Sep. 2020, M.L. Xie, HMJAU 48740; in Quercus mongolica dominated forest with Betula platyphylla and Aceraceae , alt. 770 m, 20 Sep. 2020, M.L. Xie, HMJAU 48741; Yanji County, Sandaowan Town, Wupiyegou, in Quercus mongolica forest, alt. 580 m, 7 Sep. 2018, M.L. Xie, HMJAU 44502, HMJAU 44503, HMJAU 44504; 4 Sep. 2019, M.L. Xie, HMJAU 48709, HMJAU 48710, HMJAU 48711; 22 Sep. 2020, M.L. Xie, HMJAU 48742; Sichuan Province, Xiaojin County, Siguniang Mountain, alt. 2014 m, 15 Aug. 2013, W.L. Lu, HMAS 268389, HMAS 268417, HMAS 268519; in mixed forest with Abies , alt. 3468 m, 17 Aug. 2015, T.Z. Wei & D. Wang, HMAS 274394, HMAS 274404; Balang Mountain, in mixed forest of Abies and Betula , alt. 3459 m, 18 Aug. 2015, T.Z. Wei & D. Wang, HMAS 274469, HMAS 274474; in mixed forest of Abies , Betula and Pinus , alt. 3345 m, 19 Aug. 2015, T.Z. Wei & D. Wang, HMAS 274507.

Notes: Cortinarius albocyaneus , a newly recorded species in China, is a very common species and widely distributed in the temperate zone of Northern Hemisphere. It is characterized by a greyish blue, somewhat viscid, weakly hygrophanous pileus in young or moist conditions. Phylogenetically, C. albocyaneus formed a sister relationship with North American C. caeruleoanomalus from which it differs by seven substitutions and indel positions. The nrITS sequences between Chinese specimens and epitype specimen of C. albocyaneus ( KX302206 ) are identical or have one to two substitutions.

Figures

Fig. 2. Basidiomata. A. Cortinarius albocyaneoides HMJAU 48664 (holotype). B. C. albocyaneus HMJAU 44499. C. C. azureovelatus HMJAU 48736. D. C. campanianomalus HMJAU 48692. E. C. campanianomalus HMJAU 48748 (holotype). F. C. caninus HMJAU 44372. G. C. epsomiensis HMJAU 44505. H. C. kranabetteri HMJAU 48644. Photos by M.L. Xie. Scale bars = 20 mm.

Fig. 6. Transmitted light microscopy imaging of basidiospores. A. Cortinarius albocyaneoides HMJAU 48664 (holotype). B. C. albocyaneus HMJAU 44499. C. C. azureovelatus HMJAU 48736. D. C. campanianomalus HMJAU 48748 (holotype). E. C. caninus HMJAU 44372. F. C. epsomiensis HMJAU 44505.G. C. kranabetteri HMJAU 48644.H. C. lepidopus HMJAU 48715.I. C. microalbocyaneus HMJAU 48706 (holotype). J. C. neocaninus HMJAU 48691 (holotype). K. C. perrotensis HMJAU 48662. L. C. qilianensis HMJAU 44508 (holotype). M. C. robustianomalus HMAS 254763 (holotype). N. Cortinarius rufolilacinus HMJAU 48739 (holotype). O. Cortinarius subalbocyaneus HMJAU 48659 (holotype). P. C. subanomalus HMJAU 48752 (holotype). Q. C. subclackamasensis HMJAU 48642. R. C. tabularis HMJAU 44269. S. C. vernalianomalus HMJAU 48770 (holotype). T. C. xizangensis HMAS 274227 (holotype). Photos by M.L. Xie. Scale bars = 10 µm.

Fig. 7. Scanning electron microscopy imaging of basidiospores. A. Cortinarius albocyaneoides HMJAU 48664 (holotype). B. C. albocyaneus HMJAU 44499. C. C. azureovelatus HMJAU 48736. D. C. campanianomalus HMJAU 48748 (holotype). E. C. caninus HMJAU 44372. F. C. epsomiensis HMJAU 44505.G. C. kranabetteri HMJAU 48644.H. C. lepidopus HMJAU 48715.I. C. microalbocyaneus HMJAU 48706 (holotype). J. C. neocaninus HMJAU 48691 (holotype). K. C. perrotensis HMJAU 48662. L. C. qilianensis HMJAU 44508 (holotype). M. C. robustianomalus HMAS 254763 (holotype). N. Cortinarius rufolilacinus HMJAU 48739 (holotype). O. Cortinarius subalbocyaneus HMJAU 48659 (holotype). P. C. subanomalus HMJAU 48752 (holotype). Q. C. subclackamasensis HMJAU 48642. R. C. tabularis HMJAU 44269. S. C. vernalianomalus HMJAU 48770 (holotype). T. C. xizangensis HMAS 274227 (holotype). Photos by M.L. Xie.