Cortinarius fibrillososalor P. Long & Z.H. Chen sp. nov.

Figs 2, 3

Etymology.

Fibrillososalor (Latin) refers to the species morphologically similar to Cortinarius salor, but with fibrils on the pileus.

Holotype.

China, Hunan Province: Sangzhi County, Badagongshan National Nature Reserve, at 29.782541°N, 110.084472°E, alt. 1424 m, 8 September 2020, Z.H. Chen, P. Long and S.N. Li, (MHHNU 32494).

Diagnosis.

Differs from the other species of sect. Cortinarius Delibuti from its fibrillose pileus.

Description.

Basidiomes small to medium-sized, telamonia-like, development type stipiocarpic. Pileus 2.9-5.2 cm, at first broadly convex, then lower convex to plane, broadly umbonate at the centre, margin incurved or decurved to upturned; at first violaceous (17B6-17B8), tinged brown (5B4-5C6) at the centre then becoming whitish mauve (16A1-16A2), finely fibrillose, with brown (5A5-5C7) universal veil remains at margin; surface silky when dry or glutinous when wet. Context thin, creamy white, soft, beige (3A1-A2) when bruised. Lamellae adnate to adnexed, lilac (17A2-17B2) to brownish (6C5-6D7), moderately distant, sometimes margin wavy. Stipe cylindrical to clavate, bend, gradually slender to the apex, 3.4-5.9 cm long, 0.4-0.8 cm wide, violaceous (17A4-17B5) when young then fading to whitish mauve (16A2-16A3) tint, leaving an ochraceous (5B6-5D8) ringon the upper stem, hollow. Odour indistinct.

Basidiospores [100/5/5] (6.5-) 7.0-8.8 (-9.2) × (5.0-) 5.9-7.2 (-8.1) μm, av. 8.1 × 6.5 μm, Q = 1.14 (1.16) - 1.31 (1.45), Qm = 1.24 ± 0.02, broadly globose to long ellipsoid, rarely subglobose, yellowish brown, moderately verrucose, without amyloid and dextrinoid reaction. Basidia (27-) 28-35 × (8-) 9-11 μm, 4-spored, sterigmata up to 2.4-3.7 μm, clavate to subcylindrical, colourless or with amber yellow oily inclusions or granules. Pileipellis duplex, hyphae 4-8 μm wide, epicutis strongly gelatinous, 68-128 μm thick, composed of colourless or amber yellow, irregularly arranged and strongly interwoven hyphae, hypocuits 25-38 μm thick, composed of colourless or amber yellow, nearly parallel cylindrical hyphae. Lamellar edges fertile. Cystidia absent. Lamellar trama regular, 40-80 μm thick, composed of parallel arranged hyphae, hyphae 3-6 μm wide. Stipitipellis gelatinous, stipe hyphae 3-6 μm wide, thin-walled, cylindrical, interwoven. Clamp connections present in all tissues.

Habitat, ecology and distribution.

Solitary to gregarious on soil in evergreen broad-leaved forest, known from Hunan, China; July to September.

Additional specimens examined.

China, Hunan Province: Sangzhi County, Badagongshan National Nature Reserve, at 29.769154°N, 110.086577°E, alt. 1405 m, 31 July 2020, Z.H. Chen, P. Long and S.N. Li, (MHHNU 32070) . China, Hunan Province: Sangzhi County, Badagongshan National Nature Reserve, at 29.769154°N, 110.477086°E, alt. 1482 m, 28 July 2022, Z.H. Chen, J. Wen and Z.J. Jiang (MHHNU 33509, MHHNU 33520) . China, Hunan Province: Sangzhi County, Badagongshan National Nature Reserve, at 29.404913°N, 109.491158°E, alt. 1500 m, 10 September 2015, P. Zhang, (MHHNU 8657) .

Notes.

Cortinarius fibrillososalor can be differentiated from other species of section Cortinarius Delibuti for its fibrillose pileus, usually under evergreen broad-leaved forest at 1405-1500m. In addition, basidiospores broadly globose to long ellipsoid, rarely subglobose while other members in this section usually subglobose to broadly ellipsoid.