Sarocladium yunnanense L. H. Zhu, Lin Zhou & D. W. Li 2025, sp. nov.

Sarocladium yunnanense L. H. Zhu, Lin Zhou & D. W. Li sp. nov. Fig. 5 Type. China • Yunnan Province, Xishuangbanna Prefecture, Mengla County, Menglun Town, Xishuangbanna Tropical Botanical Garden (21°55'0.12"N, 101°15'E), isolated from the dead leaves of the Washingtonia filifera, Nov. 2024, L. H. Zhu & D. W. Li. Holotype specimen CFCC 72677 is a living specimen being maintained via lyophilization at the China Forestry Culture Collection Center (CFCC). Ex-type (= WF 8-2 a 2) is maintained at the Forest Pathology Laboratory, Nanjing Forestry University. Etymology. The term ‘ yunnanense ’ indicates that this species was collected from Yunnan Province, China. Description. Asexual morph on PDA: Mycelium immersed, composed of septate, branched, white to transparent hyphae, 1.5–3 μm wide, with the aged mycelium chain-like. Conidiophores erect, arising directly from vegetative hyphae, simple, hyaline to subhyaline. Phialides solitary, straight or slightly flexuous, short needle-like, (11.3 –) 11.7–22.2 (– 25.2) μm (mean ± SD = 16.7 ± 3.4 μm, n = 20) long, with distinct periclinal thickening of the conidiogenous loci, hyaline, smooth, and thin-walled. Conidia unicellular, fusiform, (4.0 –) 4.2–7.0 (– 7.9) × (1.4 –) 1.4–2.0 (– 2.1) μm (mean ± SD = 4.8 ± 0.6 × 1.8 ± 0.2 μm, n = 50), with slightly truncate ends, initially hyaline and smooth, arranged in chains containing up to 15 spores; conidia become swollen and enlarged at a later stage, becoming subhyaline and apparently verruculose due to the production of a mucilaginous exudate, irregular or lemon-shaped with slightly truncate ends, (4.5 –) 4.5–6.8 (– 9.3) × (2.3 –) 2.3–3.7 (– 3.8) μm (mean ± SD = 5.6 ± 0.8 × 3.1 ± 0.4 μm, n = 50). Chlamydospores and sexual morph not observed. Cultural characters. Colonies on PDA 3.64–4.86 cm diam after 30 days at 25 ° C, white to cinnamon, reverse yellowish white, flat, powdery; coarse flocculent in center, aerial mycelia occasionally seen near the edge; exudates not observed. Additional strain examined. China • Yunnan Province, Xishuangbanna Prefecture, Mengla County, Menglun Town, Xishuangbanna Tropical Botanical Garden (21°55'0.12"N, 101°15'E), dead leaves of the Washingtonia filifera, Nov. 2024, L. H. Zhu & D. W. Li, WF 8-2 a 3 (CFCC 72679). Notes. Phylogenetically, Sarocladium yunnanense formed an independent lineage in the Sarocladium clade, based on the ITS + LSU sequence data, and grouped with S. subulatum, S. terricola, and S. bacillisporum with strong support (99 / 1.00). In terms of the ITS sequence, the similarities (bp difference) between S. yunnanense and S. subulatum, S. terricola and S. bacillisporum are 93.43 % (36 bp difference), 93.80 % (34 bp difference), and 90.32 % (49 bp difference), respectively. Whereas in the LSU, the similarities (bp difference) are 98.55 % (8 bp difference), 987.32 % (16 bp difference), and 97.49 % (15 bp difference), respectively. Morphologically, these species can be easily distinguished from each other. The conidia of S. yunnanense become swollen and enlarged at a later stage, irregular or lemon-shaped with slightly truncate ends, while this does not occur in the other three species (Rambaut 2018). In addition, S. yunnanense can be clearly differentiated from S. terricola and S. bacillisporum by the colour of the colony, which is white in S. terricola and pinkish in S. bacillisporum (Gams and Hawksworth 1975).