Pestalotiopsis acericola M. G. Liao & Jian Ma 2026, sp. nov.

Pestalotiopsis acericola M. G. Liao & Jian Ma sp. nov. Fig. 2 Type. China • Zhejiang Province, Hangzhou City, West Lake Scenic Area, on diseased leaves of Acer buergerianum, 22 October 2023, X. X. Luo (HJAUP M 1856, holotype), ex-type living culture, HJAUP C 1856.1 = HJAUP C 1856.2 = HJAUP C 1856.3 = HJAUP C 1856.4. Etymology. Named after the genus, Acer, from which the fungus was isolated. Description. Regular leaf spots, grey white in center with blurred margin. Asexual morph on PDA: Conidiomata acervular, globose to clavate, 350–660 μm diam., superficial, 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, 16.1–24.5 × 5.2–6.9 μm (x ̄ = 20.9 × 5.9 μm, n = 50), 4 - septate, slightly constricted at the septa; basal cell conical, 3.1–5.3 μm (x ̄ = 4.1 μm), hyaline or sometimes pale brown, smooth, thin-walled, with a single filiform appendage, unbranched, 4.6–10.7 μm (x ̄ = 7.0 μm) long; three median cells doliiform to cylindrical, smooth, thick-walled, 10.4–14.6 μm (x ̄ = 12.8 μm), concolorous, pale brown to brown, somewhat constricted at the septa, second cell from the base 3.6–5.0 µm (x ̄ = 4.4 μm) long, third cell 3.0–5.0 µm (x ̄ = 4.1 μm) long, fourth cell 3.6–5.8 µm (x ̄ = 4.6 μm) long); apical cell conical to acute, hyaline, smooth, thin-walled, 2.6–4.6 µm (x ̄ = 3.9 μm) long, with 2–3 filiform appendages, arising from the apex of the apical cell each at a different point, unbranched, 12.3–27.5 µm (x ̄ = 17.7 μm) long. Sexual morph: not observed. Culture characteristics. Colonies on PDA grow fast, filamentous, reaching 76–82 mm diam. after 5–7 days at 25 ° C in light and dark conditions (8 h / 16 h), white, with flocculent mycelium and entire edge, forming black, brown conidiomata, and reverse pale orange in center. Note. Phylogenetic analyses revealed that the four strains (HJAUP C 1856.1 T, HJAUP C 1856.2, HJAUP C 1856.3, and HJAUP C 1856.4) of P. acericola form a distinct clade sister to P. ficicrescens (HGUP 861 T and CGMCC 3.23471) with 98 % ML / 1.00 BI bootstrap support (Fig. 1). Based on a BLASTn search of P. acericola (HJAUP C 1856.1 T) and P. ficicrescens (HGUP 861 T) in GenBank, comparisons of nucleotides showed 2 bp (537 / 539, including two gaps), 1 bp (291 / 292, no gaps), and 4 bp (451 / 455, including one gap) nucleotide differences in the ITS, tef 1-α, and tub 2 regions, respectively. Moreover, P. acericola differs from P. ficicrescens Qi Yang & Yong Wang bis (Hyde et al. 2023) in its smaller conidiomata (350–660 μm diam. vs. 400–1200 μm diam.) and wider conidia (5.2–6.9 μm vs. 3–5.5 μm) with a longer fourth cell (3.6–5.8 µm vs. 3–5 µm) from the base, a longer basal appendage (4.6–10.7 μm vs. 3.5–7 µm), and longer apical appendages (12.3–27.5 μm vs. 10.5–18 µm). Furthermore, P. acericola can be distinguished from P. ficicrescens by its different host (Acer buergerianum vs. Ficus tikoua).