Trimmatostroma salicis Corda, Icon.

Trimmatostroma salicis Corda, Icon. fung. (Prague) 1: 9 (1837) (FIGURE 5) Saprobic on decaying branches of an unidentified woody plant. Sexual morph: Not observed. Asexual morph: Colonies brownish to black, macroscopically visible, caespitose or in erect tufts. Mycelium internal, hyphae not very conspicuous, sparingly branched, pale brown to brown, septate, rather thick-walled, smooth. Stromata lacking. Conidiophores immersed, cylindrical, curved or upright, pale brown, 4–7 μm (x = 5.8 μm) wide, occasionally branched, hyphal filaments gradually developing into fertile threads by becoming somewhat wider and darker. Conidiogenous cells integrated, monoblastic, poorly differentiated, 3–7 × 3–6 μm (x = 5.4 × 4.6 μm, n= 30). Conidia in basipetal chains, multicellular, straight or curved long rod, 2–13-septate, 17–45 × 4–7 μm (x = 28.3 × 5.9 μm, n= 30), pale to dark brown, wall 0.3–0.8 μm (x = 0.6 μm) thick. Culture characteristics: Conidia germinated on PDA within 12 h at 25 °C in darkness. Colonies white with a dense, uneven texture and a distinct brownish central area, with irregular and slightly raised margins, approximately 12 mm diam. on PDA after 4 weeks at 25°C; on the reverse side, bright orange, dense, and exhibits a radiating, slightly wrinkled texture with smooth and well-defined margins. Material examined: China, Sichuan Province, Aba Tibetan and Qiang Autonomous Prefecture, Li County, Miyaluo Scenic Resort, 102°48’35” E, 31°42’56” N, elevation 3207 m, on decaying branches of an unidentified woody plant, 19 October 2021, Y.P. Chen and W.H. Tian, MYL57 (HUEST 24.0139), living culture UESTCC 24.0128. Notes: BLASTn analysis showed that our newly collected isolate UESTCC 24.0128 displayed 99% sequence identity of ITS (661/663, 0 gaps), and 100% sequence identity of LSU to Trimmatostroma salicis CPC 13571. In the multilocus phylogenetic tree (FIGURE 2), isolate UESTCC 24.0128 cluster with T. salicis MFLU 18-0702 formed a strongly supported clade. Morphologically, the newly collected specimen resembles the generic type, Trimmatostroma salicis, in having much more compact and well-delimited sporodochia, up to 13-septate conidia and being non-lichenicolous (Ellis 1971, Crous et al. 2007). Therefore, we identified the newly collected specimen (HUEST 24.0139) as T. salicis, marking its first recorded occurrence in China.