Tephrocybella calocyboides X. D. Yu and J. X. Hou, 2025

Hou, Jian-Xuan, Qi, Yue, Lyu, Jin-Xin, Xu, Ai-Guo, Zhao, Jia-Chen, Guo, Hong-Bo, Yang, Rui- Heng & Yu, Xiao-Dan, 2025, Tephrocybella calocyboides sp. nov. from Liaoning Province, China and an identification key for Tephrocybella, Phytotaxa 695 (1), pp. 115-122 : 118-120

Tephrocybella calocyboides X. D. Yu and J. X. Hou , sp. nov. ( Figures 2 and 3 ).

Mycobank No: 854247

Diagnosis: Tephrocybella calocyboides differs from other closely related species by its pale orange-yellow pileus; all surfaces of basidiomata turn black when bruised.

Holotype: China. Liaoning Province, Shenyang, Shenyang Agricultural University, Tianzhu Mountain , on the soil, 90.5 m, 27 August 2019, 41°49′50.50″ N 123°34′3.3″ E, leg. X.D.Yu (SYAU-FUNGI-84).

Etymology: “ calocyboides ” refers to the bright color of the new species, similar to that of species of the genus Calocybe .

Description: Basidiomata are small. Pileus 1.5–3.0 cm in diameter, convex at first, with a constant central umbo, hygrophanous surface, pale orange–yellow (3B5–3B8), and irregularly flexuous edge. Lamellae 1.0–2.0 mm broad, slightly adnate, moderately crowded, pale orange yellow (3B5) to light orange yellow (4C5), smooth edges, and concolorous. Stipe 2.0– 3.5 cm long, 0.3–0.6 cm diameter, central, stuffed, cylindrical, slightly curving, light orange yellow (4C5) to mars yellow (4C8) at the base, some white (3A1) pruina on the surface of the stipe. Smell farinaceous. All basidiomata surfaces turned black when bruised.

Basidiospores (2.8) 3.5–4.0 (5.5) × (1.8) 2.4–2.7 (4.2) μm, Q = (1.20) 1.32–1.51 (1.97) μm (n = 30), average Q = 1.51, ellipsoid, hyaline, and inamyloid. Under an electron microscope, a small round verruculose attached to the surface of the basidiospores was observed. Each wart 0.02–0.1 μm in diameter. Basidia (15.2) 16.7–20.5 (23.5) × (2.4) 3.1–4.3 (4.9) μm, clavate, 4-spored, hyaline, siderophilous granules observed. Hymenial cystidia are absent. Hymenophoral trama 150–180 μm thick, subregular, consisting of 2.0–5.0 μm wide, thin-walled, hyaline, subparallel hyphae. Subhymenium 9.5–12.0 μm thick. Pileipellisis a cutis of dense, subparallel, repent branched hyphae, hyphae 1.8–3.5 μm wide, thin-walled, and mainly vacuolar pigment. Stipitipellis hyphae 2.3–6.5 μm wide, thin-walled, hyaline. Caulocystidia absent. Clamp connections are present everywhere, but they are not numerous.

Habitat and distribution: Saprophytic and scattered in soil near forests or roads. Known in Northeast China.

Additional specimens examined: China. Liaoning Province: Shenyang, Campus of Shenyang Agricultural University, on the soil, on August 26, 2019, 41°49′50.50″ N 123°34′3.3″ E, leg.X.D. Yu (SYAU-FUNGI-085).

Notes: Tephrocybella calocyboides is primarily characterized by its small basidiomata, pale orange-yellow pileus, concolorous and adnate lamellae, blackening when bruised, and verruculose basidiospores. Tephrocybella calocyboides clustered with T. griseonigrescens and T. constrictospora in a well-supported clade (1.00 PP and 100% BS). The basidiomata of T. calocyboides and T. griseonigrescens turn black when bruised, whereas T. calocyboides has a pale orange-yellow pileus, and T. griseonigrescens has a pale grayish pileus. The pileus surface of T. constrictospora is ochraceous brown; therefore, it differs from that of T. calocyboides . Moreover, T. calocyboides lacks cheilocystidia, whereas T. griseonigrescens and T. constrictospora have them (Clericuzio et al. 2017).

Figures

FIGURE 2. Tephrocybella calocyboides, SYAU-FUNGI-084 (Holotype). (A) Basidiomata; (B) Blackening when bruised; (C) Lamellae; (D) Section. Scale bars: (A–D) 10 mm. (E) Basidia. (F) Basidiospores. (G) Cells of pileipellis. Scale bars: (E–G) 5 μm.

FIGURE 3. Tephrocybella calocyboides, SYAU-FUNGI-084 (Holotype). (A) Basidiomata in the natural habitat. Scale bars: 20 mm; (B) SEM photos of basidiospores. Scale bars: 2 μm.