Pestalotiopsis hederae X. X. Luo & Jian Ma 2024, sp. nov.

Pestalotiopsis hederae X. X. Luo & Jian Ma sp. nov. Fig. 7 Type. China • Yunnan Province, Jinghong City, Menghan Town, Xishuangbanna Dai Nationality Garden; on diseased leaves of Hedera helix; 22 June 2022, X. X. Luo (holotype HJAUP M 1638.221; ex-type living culture HJAUP C 1638.221). Etymology. Referring to the host genus, Hedera from which it was collected. Description. Regular leaf spots, grey-brown in the center and darkening to black brown at the margins. Asexual morph on PDA: Conidiomata acervular, globose, 660–1570 μm diam., solitary or aggregated in clusters, black. Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to ampulliform. Conidia fusiform, straight or slightly curved, 15.8–22.4 × 4.9–6.3 μm (x ̄ = 18.0 × 5.7 μm, n = 50), 4 - septate, slightly constricted at the septa, basal cell conical, 3.1–5.3 μm (x ̄ = 4 μm), hyaline or sometimes pale brown, smooth, thin-walled, with a single filiform appendage, unbranched, 3.4–5.9 μm (x ̄ = 4.8 μm) long; three median cells doliiform to cylindrical, smooth, thick-walled, 11.1–15.5 μm (x ̄ = 13.6 μm), pale brown to brown, concolorous, somewhat constricted at the septa, second cell from the base 3.7–5.3 μm (x ̄ = 4.7 μm) long, third cell 4.3–5.6 μm (x ̄ = 4.9 μm) long, fourth cell 4.2–5.6 μm (x ̄ = 5 μm) long; apical cell conical to acute, hyaline, smooth, thin-walled, 3.3–5 µm (x ̄ = 4.1 μm) long, with 2 (– 3) filiform appendages, arising from the apex of the apical cell each at a different point, unbranched, 10.8–19.6 µm (x ̄ = 15.5 μm) long. Sexual morph not observed. Culture characteristics. Colonies on PDA grow fast, filamentous to circular, growing all over the Petri dish at 25 ° C in darkness, regular edge, white, sparse aerial mycelium on the surface, forming black conidiomata with black conidial masses, and reverse pale orange or white at the margin, dark brown at the center. Additional specimen examined. China • Yunnan Province, Jinghong City, Menghan Town, Xishuangbanna Dai Nationality Garden, 22 June 2022, X. X. Luo. On diseased leaves of Hedera helix, paratype HJAUP M 1638.222, living culture HJAUP C 1638.222. Note. Two strains (HJAUP C 1638.221 and HJAUP C 1638.222) of Pestalotiopsis hederae isolated from leaf spots of Hedera helix formed a distinct clade sister to P. hydei (MFLUCC 20–0135) with 94 % ML / 0.95 BI bootstrap support (Fig. 1). The ex-type strain HJAUP C 1638.221 is closely related to P. hydei (MFLUCC 20–0135) and comparisons of their nucleotides showed 10 bp differences (1 %, including two gaps) nucleotide differences in three loci, respectively. Moreover, P. hederae is morphologically distinguished from P. hydei Huanraluek & Jayaward., which has longer conidia (18–35 μm vs. 15.8–22.4 μm) with minutely verruculose three median cells and shorter apical appendages (3–12 µm vs. 10.8–19.6 µm) (Huanaluek et al. 2021).