Phylogenomics, taxonomy and morphological characters of the Microdochiaceae (Xylariales, Sordariomycetes) Author Zhang, Zhao-Xue 0000-0002-4824-9716 Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, 271018, China Author Shang, Yu-Xin Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, 271018, China Author Zhang, Meng-Yuan Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, 271018, China Author Zhang, Jin-Jia Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, 271018, China Author Geng, Yun Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, 250100, China Author Xia, Ji-Wen 0000-0002-7436-7249 Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, 271018, China Author Zhang, Xiu-Guo Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, 271018, China text MycoKeys 2024 2024-07-03 106 303 325 journal article 299503 10.3897/mycokeys.106.127355 f6bae5fa-e965-4226-beb7-7ec50d05b242 Microdochium australe Z. X. Zhang, & X. G. Zhang sp. nov. Fig. 5 Type . China , Hainan Province , Jianfengling National Forest Park, on diseased leaves of Phragmites australis , 13 October 2023 , Z . X. Zhang ( HMAS 352973, holotype ), ex-holotype culture SAUCC 6322-5 - 1. Etymology. Referring to the species name of the host plant Phragmites australis . Description. Endogenic on diseased leaves of Phragmites australis . Mycelia are superficial and immersed, 3–3.3 µm wide, branched, membranous and hyaline. Sporodochia black, aggregative or solitary. Conidiophores are indistinct and often reduced to conidiogenous cells. Conidiogenous cells are straight or slightly curved, 15.4–23.5 × 2.8–4 µm, terminal, hyaline, septate, ampulliform or obpyriform, smooth. Conidia are solitary, hyaline, straight to slight curved, oblong to ellipsoid, 11.3–16.1 × 2.5–3.7 µm, multi-guttulate, (2) 3 - septate, apex rounded, base usually flattened. Sexual morphs were not observed, chlamydospores were not observed, see Fig. 5 . Figure 5. Microdochium australe (HMAS 352973, holotype) a a leaf of Phragmites australis b, c colonies on PDA from above and below after 14 days d colony overview e, f conidiogenous cells and conidia g, h conidia. Scale bars: 10 μm ( e – h ). Culture characteristics. Cultures incubated on PDA at 25 ° C in darkness, reaching 73–76 mm diam., had a growth rate of 5.2–5.4 mm / day after 14 days, with moderate aerial mycelia, milky white to grey-white, with regular margin, and sporodochia are observed, reverses black to brown in the centre, with grey-white and regular margin. Additional material studied. China , Hainan Province , Jianfengling National Forest Park, on saprophytic leaves, 13 October 2023 , Z . X. Zhang ( HSAUP 6151-1), living culture SAUCC 6151-1. Notes. Phylogenetic analyses showed that Microdochium australe sp. nov. formed an independent clade closely related to Microdochium bambusae and Microdochium indocalami (Fig. 1 ). Mi. australe was distinguished from Mi. bambusae ( SAUCC 1862-1) by 47 / 503, 2 / 836, 56 / 848 and 17 / 710 base pair differences, from Mi. bambusae and Mi. indocalami (SAUCC 1016) by 52 / 503, 2 / 848, 44 / 840 and 17 / 708 base pairs in ITS , LSU , RPB 2 and TUB 2 sequences, respectively. Morphologically, Mi. australe (11.3–16.1 × 2.5–3.7 µm, (2) 3 - septate) differs from Mi. bambusae (13.0–17 × 2.5–3.5 μm, aseptate) and Mi. indocalami in conidia (13–15.5 × 3.5–5.5 μm, 3 - septate), and, therefore, we described this fungus as a novel species.