Cortinarius coriaceus Zhu L. Yang, Liu K. Jia & Zi R. Wang, 2025

Cortinarius coriaceus Zhu L. Yang, Liu K. Jia & Zi R. Wang sp. nov.

Fig. 3 View Figure 3

Etymology.

The epithet “ coriaceus ” (Lat.) refers to the brown pileus with a leathery texture of this species.

Holotype.

China • Yunnan Province: Lijiang City, Yulong Naxi Autonomous County, Lijiang Alpine Botanical Garden , in a subalpine temperate broad-leaved and coniferous mixed forest with trees of Quercus and Pinus , 27°0.21'N, 100°10.71'E, elevation 3,340 m, 7 August 2023, Dong-Mei Li 299 ( KUN-HKAS 145316 ). GenBank: ITS: PQ 772202, nrLSU: PQ 772214 GoogleMaps .

Diagnosis.

Cortinarius coriaceus looks like C. odoritraganus Niskanen, Liimat. & Ammirati , but differs in its emarginate lamellae, cylindrical stipe, and relatively larger basidiospores ( Niskanen 2020).

Description.

Basidioma medium-sized to large. Pileus 3 cm diam when young, 4.5–7 cm diam when mature, initially slightly campanulate, becoming plano-convex, occasionally with slightly subumbonate center, viscid, with a leathery texture; brown (6 C 4–6 C 7), paler (6 A 2–6 A 4) towards the center, covered with white (1 A 1) fibrillose squamules when young; pale brown to brown (6 A 4–6 C 4), pale brown (6 A 2), or dark brown (6 D 4–6 D 6) towards the center when mature; margin incurved, with innate radial brownish (6 C 2–6 C 3) stripes when young; context of pileus pale brown to brown (6 A 3–6 B 3, 6 C 6). Lamellae emarginate, medium-spaced (L = 38–52, l = 27–36), pale brown (6 A 4) with a faint pinkish (12 A 2) tint when young, later brown (6 C 4–6 C 7). Stipe 4.5–6 × 0.7–1.2 cm, cylindrical, dirty white (1 A 1–1 B 1) and pale violaceous (16 A 2–16 A 4), with more and more violaceous (16 A 4) tint towards the stipe apex when young, later dirty white (1 A 1–1 B 1), pale brown (6 B 2–6 B 4), covered with brown (6 C 6) to dark brown (6 D 6) fibrillose squamules; annulus cortinate; context of stipe dirty white (1 A 1–1 B 1) with brown (6 C 6); basal mycelium white (1 A 1).

Basidiospores [60 / 3 / 3] (10 –) 11.5–12.5 (– 14) × (5 –) 7.5–10 μm, Q = 1.25–1.43 (– 1.66), av. = 12.06 ± 0.85 × 8.33 ± 1.48 μm, Qav. = 1.48 ± 0.24, ellipsoid to amygdaliform, moderately to strongly verrucose, inamyloid. Basidia 37.5–43 × 7.5–10 μm, 4 - spored, clavate. Trama of lamellae regular, composed of colorless to yellowish, smooth hyphae 12.5–15 μm wide. Cystidia absent. Pileipellis duplex: epicutis weakly developed, 15–20 μm thick, composed of only 2–3 layers of interwoven to parallel, colorless, smooth, thin-walled, long-celled hyphae 3–7.5 µm wide; hypocutis composed of interwoven to parallel, colorless, cylindrical, thin-walled hyphae 12.5–17.5 μm wide. Clamp connections common in all parts of basidioma.

Habitat / host.

Summer. Solitary or gregarious on soil in subalpine temperate broad-leaved and coniferous mixed forests with trees of Quercus and Pinus .

Distribution.

Currently known from southwestern China.

Additional specimens examined.

China • Yunnan Province: Lijiang City, Yulong Naxi Autonomous County, Lijiang Alpine Botanical Garden , in a subalpine temperate broad-leaved and coniferous mixed forest with trees of Quercus and Pinus , 27°0.21'N, 100°10.71'E, elevation 3,340 m, 7 August 2023, Guan-Rui Li 328 ( KUN-HKAS 145314 ) GoogleMaps , same place and date, Guan-Rui Li 333 ( KUN-HKAS 145315 GoogleMaps ).

Notes.

Cortinarius coriaceus is characterized by its brown, leathery-wrinkled pileus, pinkish-tinted lamellae, and relatively larger basidiospores.

Cortinarius coriaceus is phylogenetically closely related to and morphologically similar to C. odoritraganus , known from Eastern North America and Costa Rica, in mixed temperate forest with Abies and Betula or mountain Quercus forest. However, C. odoritraganus differs in its paler pileus, adnexed, purple-brown to brown lamellae, longer and thicker stipe (5–10 × 1–2 cm), and relatively smaller basidiospores (9.5–11.5 × 6–7.5 μm) ( Niskanen 2020). Cortinarius niveotraganus Kytöv., Niskanen & Liimat. , another related species, is distinguished by its hemispherical to broadly convex pileus, initially white to greyish white lamellae with bluish tints, clavate stipe, relatively smaller basidiospores (8.6–10.9 × 5.2–6.3 μm), and occurrence in planted Betula forests ( Niskanen 2014).