Sirococcus euryicola Y. L. Wang, Z. X. Zhang, M. Y. Zhang 2026, sp. nov.

Sirococcus euryicola Y. L. Wang, Z. X. Zhang, M. Y. Zhang sp. nov. Fig. 2 Type. China. • Yunnan Province: Mopanshan National Forest Park, 23°10'01"N, 101°09'37"E, ca. 2,123 m a. s. l., isolated from healthy leaves of Eurya japonica, 13 May 2024, coll. Y. L. Wang (holotype: dried culture, HSAUP 8416; ex-holotype culture CGMCC 3.40298). Etymology. The specific epithet euryicola refers to the host plant Eurya japonica. Description. Sexual morph not observed. Asexual morph: pycnidial conidiomata solitary, yellowish-brown, producing hyaline conidial masses after 10 d of incubation on WA at 25 ° C in darkness. Conidiophores hyaline, smooth, indistinct, mostly reduced to conidiogenous cells. Conidiogenous cells phialidic, hyaline, smooth, cylindrical to ampulliform, 6.4–15.3 × 1.2–2.3 μm. Conidia hyaline, smooth, guttulate, obovoid to oval-fusoid, straight or slightly curved, base acute, (5.3 –) 6.2–7.8 (– 9.4) × (1.4 –) 1.6–2.0 (– 2.2) μm, mean ± SD = 6.99 ± 0.82 × 1.79 ± 0.16 μm, n = 46. Culture characteristics. Colonies on PDA attaining 73–74 mm diam. after 7 d at 25 ° C in darkness, petaloid, greyish-white, moderate aerial mycelium; margin undulate; reverse concolorous; no diffusible pigments. Additional materials examined. China. • Yunnan Province: Mopanshan National Forest Park, 23°10'01"N, 101°09'37"E, ca. 2,123 m a. s. l., on healthy leaves of Eurya japonica, 13 May 2024, coll. Y. L. Wang, culture SAUCC 8420. Notes. Multilocus phylogenetic analysis based on the combined ITS, tef 1, and tub 2 sequence dataset reveals that S. euryicola forms a highly supported monophyletic clade (MLBS = 100 %, BIPP = 1.00) within Sirococcus and is sister to S. mengyinensis (Fig. 1). Pairwise sequence comparisons show that S. euryicola differs from S. mengyinensis (SAUCC MY 0293, ex-type) by 1.9 % (9 / 485), 11.5 % (69 / 600), and 6.8 % (31 / 453) nucleotide divergence in the ITS, tef 1, and tub 2 regions, respectively. Sirococcus euryicola is morphologically distinguished from S. mengyinensis by its longer, more slender and predominantly obovoid conidia ((5.3 –) 6.2–7.8 (– 9.4) × (1.4 –) 1.6–2.0 (– 2.2) μm), whereas conidia of S. mengyinensis are mostly cylindrical (4.5–6.5 × 1.8–2.8 μm) (Wang et al. 2022). This species is currently known only from healthy leaves of Eurya japonica in Yunnan Province, China.