Cyclocybe dinggyensis R.L. Zhao & X.Y. Zhu, 2023

Zhu, Xin-Yu, Nyima, Tenzin, Vizzini, Alfredo, He, Mao-Qiang, Phurbu, Dorji & Zhao, Rui- Lin, 2023, Two new species of Cyclocybe (Agaricales, Tubariaceae) from China, Phytotaxa 620 (1), pp. 33-46 : 41-43

Cyclocybe dinggyensis R.L. Zhao & X.Y. Zhu sp. nov.

Fungal Names No: 571269

FoF number: 13982

Figs 3C, D , 5

Diagnosis. Basidioma slender. It differs from C. erebia in the number of spores, C. erebia is bisporic, C. dinggyensis is tetrasporic. It differs from C. erebioides in annulus, C. erebioides with a wide and complex membranous annulus, C. dinggyensis with a simple membranous annulus, and C. erebioides with clamp-connections, but C. dinggyensis clampless hyphae.

Etymology: the epithet “dinggye” refers to Dinggyê County where the type specimen is from.

Description. Basidiomes small. Pileus 20 mm in diam., broadly convex to convex, not distinctly depressed or umbo, hygrophanous, viscid, glabrous, brown to darker brown, generally darker in the center and almost brown in the margin, margin distinctly striate, not involute. Context thin, up to 1 mm, concolorous with pileus surface. Lamellae subdecurrent, thick, crowded, with series of 1–3 lamellulae, light brown. Stipe 43 × 4 mm, central, cylindrical, hollow, dry, fibrous, with annular zone, concolorous with pileus surface, daker at the base. Annulus single, concolorous with lamellae, membranous, persistent, upturned. Odor not distinctive. Taste indistinct.

Basidiospores 7.4–9.2 × 3.6–5.2 μm, [x = 8.4 ± 0.4 × 4.4 ± 0.4, Q = 1.7–2.2, Q m = 1.9 ± 0.1, n =20], oblong, subellipsoid to subamygdaliform,smooth, thick-walled, some oil-like droplets, no germ pore, brownish to brown in. Basidia 22.4–35.6 × 6.2–8.8 μm, clavate, 4-spored, most middle constrained, thin walled, hyaline. Pleurocystidia 46.7–59.7 × 9.2–13.0 μm, generally utriform, sometimes cylindrical, thin-walled, hyaline, numerous. Cheilocystidia 26.7–42.7 × 7.3–13.2 μm, similar to pleurocystidia but lacking cylindrical, mostly utriform, thin walled, hyaline. Hymenophoral trama subregular, consisting of 3.0–7.0 μm-wide hyphae. Pileipellis hymeniform formed by vesicular to clavate elements, 11.2–23.6 × 6.7–11.1 μm. Pileocystidia not observed. Caulocysidia not observed. Clamp-connections absent.

Habitat, ecology and distribution. Solitary on the ground, known from Tibet, China; from July to October.

Material examined. China. Tibet: Shigatse, Dinggyê county (27°55’15” N, 87°21’37” E), alt. 3060 m, 29 July 2022, collected by Mao-Qiang He, Bin Cao, Jia-Xin Li. ZRL20220414 (Holotype: HMAS 286979 ) .

Figures

FIGURE 3. Basidiomes of the two new Cyclocybe species. A, B Cyclocybe suberebia (HMAS-286977) C, D Cyclocybe dinggyensis (HMAS-286979). Scale bars: 1 cm.

FIGURE 5. Microscopic features of Cyclocybe dinggyensis (HMAS 286979, holotype) A, Basidiospores B, Basidia C, Pleurocystidia D, Cheilocystidia E, Pileipellis hymeniphorm.