Exidia punctata L. Wang & C.L. Zhao, 2025

Jiang, Yingtao, Wang, Lu, Zhou, Chunqin, Shen, Kaize, Zhang, Sicheng, Yang, Ali & Zhao, Changlin, 2025, Molecular phylogeny and morphology reveal a new species of Exidia (Auriculariaceae, Auriculariales) from Yunnan Province, China, Phytotaxa 689 (1), pp. 27-39 : 33

Exidia punctata L. Wang & C.L. Zhao , sp. nov. FIGS. 3–5

MycoBank no.: 856963

Diagnosis: Differs from other Exidia species by the smooth hymenophore with white to cream hymenial surface, monomitic hyphal system with clamped generative hyphae and allantoid basidiospores (13–15.5 × 5–6.5 µm).

Typification: CHINA. Yunnan Province: Lincang, Fengqing County, Yaojie, Xingyuan, GPS coordinates: 24°15′ N, 99°55′ E, altitude: 1600 m asl., on the fallen angiosperm branch, leg. C.L. Zhao, 23 October 2022, CLZhao 25823 (SWFC!).

Etymology: punctata (Lat.) : refers to the species having dotted basidiomata.

Basidiomata: Annual, resupinate, closely adnate, membranaceous when dry, without odor or taste when fresh, up to 5 cm long, 3 cm wide, and 400 μm thick. Hymenophore smooth, white (60) when fresh, white (60) to cream (4A2/3) upon drying. Sterile margin narrow, cream (4A2/3), up to 1 mm.

Hyphal system: Monomitic; generative hyphae with clamp connections, colorless, thin- to thick-walled, smooth, rarely branched, interwoven, 1–3 µm in diameter; IKI–, CB–; tissues unchanged in KOH.

Hymenium: Cystidia and cystidioles absent. Basidia narrowly ovoid to ellipsoid, longitudinally septate, fourcelled, with a basal clamp septum and four sterigmata (2–20 × 2–4 µm), 18.5–20 × 9–11.5 µm; basidioles numerous, in shape similar to basidia but smaller, 18–19.5 × 9–10 µm.

Spores: Basidiospores allantoid, with a distinct apiculus, colorless, thin-walled, smooth, usually with one or more oil drops, IKI–, CB–, 13–15.5(–17) × 5–6.5(–7) µm, L = 14.18 µm, W = 5.69 µm, Q = 2.19–2.49 (n = 60/2).

Additional specimen examined (paratype) — CHINA. Yunnan Province: Zhaotong, Wumengshan National Nature Reserve, GPS coordinates: 27°46′ N, 104°15′ E, altitude: 1900 m asl., on the fallen angiosperm branch, leg. C.L. Zhao, 21 September 2023, CLZhao 33767 (SWFC!).

Figures

FIGURE 3. Basidiomata of Exidia punctata (holotype CLZhao 25823). Scale bars: 1 cm (A); 1 mm (B).

FIGURE 4. Microscopic structures of Exidia punctata (holotype CLZhao 25823): (A) basidiospores; (B) basidia and basidioles; (C) a section of the hymenium. Scale bars: 10 µm (A–C).

FIGURE 5. Microscopic structures of Exidia punctata (holotype CLZhao 25823): (A) basidiospores; (B) basidia; (C) basidioles; (D) a section of context. Scale bars: 10 µm (A–D); 10 × 100 Oil.