Sirococcus linderae Y. L. Wang, Z. X. Dong, Y. X. Shang 2026, sp. nov.

Sirococcus linderae Y. L. Wang, Z. X. Dong, Y. X. Shang sp. nov. Fig. 4 Type. China. • Fujian Province: Wuyishan Da’anyuan Ecological Tourism Scenic Area, 27°09'13"N, 117°08'56"E; ca. 497 m a. s. l., on healthy leaves of Lindera aggregata, 20 October 2024, coll. Y. L. Wang (holotype: dried culture, HSAUP 11003; ex-holotype culture CGMCC 3.40299). Etymology. The specific epithet linderae refers to the host plant Lindera aggregata. Description. Sexual morph not observed. Asexual morph: pycnidial conidiomata solitary, globose to pulvinate, reddish-brown; hyaline conidial masses exuded after 14 d on WA at 25 ° C in darkness. Conidiophores hyaline, smooth, mostly reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform, 9.4–13.4 × 1.2–2.2 μm. Conidia hyaline, smooth, guttulate, obovoid to oval fusoid, base truncate, (3.8 –) 4.8–6.0 (– 6.5) × (2.0 –) 2.2–2.6 (– 2.8) μm, mean ± SD = 5.44 ± 0.61 × 2.42 ± 0.20 μm, n = 33. Culture characteristics. Colonies on PDA attaining 45–50 mm diam. after 7 d at 25 ° C in darkness; petaloid, greyish-white, moderate aerial mycelium; margin undulate; reverse concolorous. Additional materials examined. China. • Fujian Province: Wuyishan Da’anyuan Ecological Tourism Scenic Area, 27°09'13"N, 117°08'56"E; ca. 497 m a. s. l., on healthy leaves of Lindera aggregata, 20 October 2024, coll. Y. L. Wang, culture SAUCC 11015. Notes. Multilocus phylogenetic analysis based on the combined ITS, tef 1, and tub 2 sequence dataset revealed that S. linderae forms a highly supported monophyletic clade (MLBS = 100 %, BIPP = 1.00) within Sirococcus, sister to S. lanceolatae (Fig. 1). Pairwise sequence comparisons show that S. linderae differs from the ex-type strain of S. lanceolatae (CGMCC 3.28232) by 8.5 % (51 / 597), 39.2 % (245 / 625), and 28.1 % (108 / 384) nucleotide differences in the ITS, tef 1, and tub 2 loci, respectively. Morphologically, S. linderae can be readily distinguished from S. lanceolatae by its characteristic petaloid colonies on PDA (Zhang et al. 2025). In addition, marked differences in conidial dimensions further separate the two species: conidia of S. linderae measure (3.8 –) 4.8–6.0 (– 6.5) × (2.0 –) 2.2–2.6 (– 2.8) μm, whereas those of S. lanceolatae are 5.5–8.5 × 1.3–1.8 μm. Based on congruent morphological and multilocus phylogenetic evidence, we formally describe Sirococcus linderae as a new species.