Tryblidiopsis changbaishanensis Lan Zhuo & C. L. Hou 2025, sp. nov.

Tryblidiopsis changbaishanensis Lan Zhuo & C. L. Hou sp. nov. Figs 34, 35 Etymology. Referring to the name of the location (Changbaishan) where the type specimen was collected. Diagnosis. This new species is similar to Tryblidiopsis sinensis, but differs by having a brown covering stroma, curved ascospores, and tips of paraphyses strongly swollen to 3–5 µm. Type. CHINA, Jilin Province, Yanbian Chaoxianzu Autonomous Prefecture, Antu County, Changbaishan, 42.0867°N, 128.0745°E, alt. ca. 1600 m, on twigs of Picea jezoensis var. komarovii (V. N. Vassil.) W. C. Cheng & L. K. Fu (Pinaceae), 14 Jun. 2024, C. L. Hou, L. Zhuo, and Y. Gao, HOU 2210 (BJTC 2024070, holotype). Sexual morph. Ascomata on twigs, erumpent from bark, scattered, not associated with pale areas. In surface view, ascomata round to elliptical, 1000–1450 × 800–1250 µm, as seen from the side 600–800 µm high, brown (# 48240 a) to dark brown (# 2 b 180 b), opening by irregular splits to expose a yellow (# ffe 562) hymenium. Lips absent. In median vertical section, covering stroma 40–60 μm thick near center of ascomata, consisting of an outer layer of carbonized, angular to globose cells and an inner layer of hyaline, angular to globose cells. Basal Covering stroma 5–7 µm thick, located between the subhymenium and the internal matrix of the Covering stroma, consisting of brown to dark brown globose cells. Internal matrix of Covering stroma well-developed, consisting of hyaline, thin-walled, gelatinous cells and hyaline hyphae, mixed with irregular crystals. Subhymenium 15–20 µm thick, consisting of textura intricata and hyaline, angular to globose cells. Paraphyses aseptate, filiform, not branched, swollen to 3–5 µm at tips, 120–140 × 2 µm. Asci ripening sequentially, clavate, apex obtuse, 110–120 × 15–22 µm, thin-walled, J –, 8 - spored. Ascospores aseptate, curved fusiform, 16–25 × 4–5 μm, hyaline, covered by a 3–4 µm thick gelatinous sheath. Asexual morph. Conidiomata and zone lines not seen. Additional specimens examined. CHINA, Jilin Province, Yanbian Chaoxianzu Autonomous Prefecture, Antu County, Changbaishan, 42.0867°N, 128.0745°E, alt. ca. 1600 m, on twigs of Picea jezoensis var. komarovii (Pinaceae), 14 Jun. 2024, C. L. Hou, L. Zhuo, and Y. Gao, HOU 2211 (BJTC 2024071). Distribution. Known only from Jilin Province, China. Notes. Wang et al. (2017) cited the immature specimen of Tryblidiopsis sp. (HOU 662) on Picea jezoensis (Siebold & Zucc.) Carrière collected from Jilin Province, Changbaishan. In the context of the present study, we returned to this original collection site and successfully collected the mature specimens HOU 2210 and HOU 2211. The nrITS similarity between the newly collected specimens and HOU 662 is 98 %. Furthermore, phylogenetic analysis shows that the newly collected specimens and specimen HOU 662 cluster together. These results indicate that the newly collected specimens HOU 2210 and HOU 2211 are the same species as specimen HOU 662. The sequences of Try. changbaishanensis form a sister clade with the sequences of Try. pinastri and Try. sinensis. Tryblidiopsis changbaishanensis differs from Try. pinastri by having aseptate ascospores and tips of paraphyses strongly swollen to 3–5 µm. Tryblidiopsis changbaishanensis differs from Try. sinensis by having curved ascospores and a melanized basal Covering stroma between the subhymenium and the internal matrix of Covering stroma.