Clavulinopsis wumengshanensis S. Y. He., H. M. Zhou & C. L. Zhao 2025, sp. nov.

Clavulinopsis wumengshanensis S. Y. He., H. M. Zhou & C. L. Zhao sp. nov. Figs 4, 5 Diagnosis. Clavulinopsis wumengshanensis differs from C. aurantiocinnabarina by buff-yellow to straw-yellow basidiomata and thick-walled, subglobose, and longer basidiospores (7–8.5 µm vs. 5.6–7.1 µm). Holotype. China • Yunnan Province, Zhaotong, Yiliang County, Wumengshan National Nature Reserve, GPS coordinates 27°30'N, 104°12'E, evel. 1710 m asl., on the ground, leg. C. L. Zhao, 12 July 2023, CLZhao 29612 (SWFC). Etymology. Wumengshanensis (Lat.) refers to the locality “ Wumengshan National Nature Reserve ” of the holotype. Basidiomata. Basidiomes annual, clavarioid, without odor or taste when fresh, up to 8 cm long, 4 mm wide, and 400–800 µm thick. Fertile part subcylindrical to fusiform, occasionally slightly curved or flexuous and with a distinct longitudinal depression, buff-yellow (4 A 4) to straw-yellow (3 A / B 3) when dry. Apex rounded or obtuse acute when mature, concolourous or slightly paler. Hyphal structure. Monomitic, generative hyphae with clamp connections, hyaline, thick-walled, parallel, interwoven, 2–3 µm in diam, some inflated to 13 µm in diam, IKI –, CB –; tissues unchanged in KOH. Cystidia absent. Basidia clavate to subcylindrical, hyaline, thin-walled, with four sterigmata and a basal clamp connection, 35–48.5 × 9–11.5 µm; basidioles in shape similar to basidia, with several guttules. Spores. Basidiospores subglobose with a distinct apiculus, hyaline, thick-walled, smooth, with several guttules, IKI –, CB –, 7–8.5 (– 5) × (5.5 –) 6–7.5 µm, L = 7.59 µm, W = 6.54 µm, Q = 1.14–1.16 (n = 60 / 2). Additional specimen examined (paratype). China • Yunnan Province, Zhaotong, Yiliang County, Wumengshan National Nature Reserve, GPS coordinates 27°30'N, 104°12'E, evel. 1710 m asl., on the ground, leg. C. L. Zhao, 12 July 2023, CLZhao 29651 (SWFC). Notes. Based on the ITS + LSU analysis (Fig. 1), the result showed that the new species Clavulinopsis wumengshanensis is grouped with C. aurantiocinnabarina (Schwein.) Corner. However, C. aurantiocinnabarina differs from C. wumengshanensis by its thin-walled basidiospores and narrower basidia (5.2–7.1 µm vs. 9–11.5 µm, Petersen 1978).