Tryblidiopsis multiseptata Lan Zhuo & C. L. Hou, 2025

Zhuo, Lan, Wang, Hai-Qi, Zhang, Peng, Sui, Xiao-Nan, Guo, Mei-Jun, Wang, Shi-Juan & Hou, Cheng-Lin, 2025, New genera and species of coniferous twig-inhabiting Rhytismatales from China, IMA Fungus 16, pp. e 138790-e 138790 : e138790-

Tryblidiopsis multiseptata Lan Zhuo & C. L. Hou sp. nov.

Figs 38 , 39

Etymology.

Referring to ascospores with 3–6 septae.

Diagnosis.

This new species is distinguished from other Tryblidiopsis species by its 4 - spored asci and 3–6 - septate ascospores.

Type.

CHINA, Yunnan Province, Lijiang, Laojunshan , 26.6452°N, 99.7838°E, alt. ca. 3290 m, on twigs of Picea likiangensis ( Pinaceae ), 17 Aug. 2023, C. L. Hou, L. Zhuo, and S. Y. Zhao, HOU 2107 ( BJTC 2023238 , holotype) .

Sexual morph.

Ascomata on twigs, erumpent from the bark, scattered, not associated with pale areas. In surface view, ascomata subround to elliptical, 1500–2200 × 1100–1400 µm, as seen from the side 600–800 µm high, black (# 000000), opening by irregular splits to expose a dark gray (# 373737) hymenium. Lips absent. In median vertical section, covering stroma 35–60 μm thick near the 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 absent. Internal matrix of the Covering stroma well-developed, consisting of hyaline hyphae, filled with irregular crystals. Subhymenium 25–35 µm thick, consisting of hyaline, angular to globose cells. Paraphyses aseptate, filiform, not branched, slightly swollen at tips, 160–185 × 1 µm, covered by a ca. 1 µm thick gelatinous sheath. Asci ripening sequentially, clavate, apex obtuse, 120–150 × 18–25 µm, thin-walled, J –, 4 - spored, no aborted ascospores were observed. Ascospores 3–6 - septate, rod-shape, tapering to narrow base, 40–50 × 4–6 μm, hyaline, covered by a 2–3 µm thick gelatinous sheath.

Asexual morph.

Conidiomata and zone lines not seen.

Additional specimens examined.

CHINA, Yunnan Province, Lijiang, Laojunshan , 26.6452°N, 99.7838°E, alt. ca. 3290 m, on twigs of Picea likiangensis ( Pinaceae ), 17 Aug. 2023, C. L. Hou, L. Zhuo, and S. Y. Zhao, HOU 2104 ( BJTC 2023234 ) ; 26.6619°N, 99.7758°E, alt. ca. 3280 m, on twigs of Pi. likiangensis , 20 Jun. 2021, C. L. Hou, M. J. Guo, and H. Zhou, HOU 1750 ( BJTC 2021061 ) .

Distribution.

Known only from Yunnan Province, China.

Notes.

The phylogenetic analysis shows that sequences of this new species form a separate clade and cluster with sequences of Try. changbaishanensis , Try. magnesii , Try. melanostroma , Try. pinastri , Try. sichuanensis , and Try. sinensis . Morphologically, Try. multiseptata can be distinguished from other Tryblidiopsis species by its 4 - spored asci and 3–6 - septate ascospores.

Figures

Figure 38. Tryblidiopsis multiseptata (HOU 2107 / BJTC 2023238, holotype) a ascomata on a twig of Picea likiangensis b, c mature ascomata. Scale bars: 2 mm (a); 1 mm (b); 500 μm (c).

Figure 39. Tryblidiopsis multiseptata on Picea likiangensis (HOU 2107 / BJTC 2023238, holotype) a part of an ascoma in vertical section b paraphyses, mature asci with ascospores, and immature ascus c liberated ascospores. Scale bars: 100 μm (a); 10 μm (b, c).