Neohelicomyces puerensis M. Y. Han & Tibpromma S. 2026, sp. nov.

Neohelicomyces puerensis M. Y. Han & Tibpromma S. sp. nov. Fig. 3 Etymology. The species name “puerensis” refers to the type locality, Pu’er City, China. Holotype. GMB -W 1485. Description. Saprobic on dead branches of C. arabica. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on natural substrate superficial, effuse, gregarious, white, can be seen as a white bush with the naked eye. Mycelium partly immersed, partly superficial, composed of hyaline to pale brown, branched, septate, smooth hyphae, comprising glistening conidial mass. Conidiophores 138.8–211.7 × 2.6–4.2 μm (x ̄ = 182.4 × 3.4 μm, n = 30), macronematous, mononematous, some arising from creeping hyphae, erect, cylindrical, straight or slightly flexuous, unbranched or occasionally branched, septate, pale brown to brown at base, paler towards the apex, thick-walled. Conidiogenous cells 11.6–20 × 2.4–4.1 μm (x ̄ = 14.8 × 3.2 μm, n = 25), holoblastic, monoblastic or polyblastic, integrated, terminal or intercalary, cylindrical, with denticles, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, tapering towards the rounded ends, developing on a tooth-like protrusion, 15.2–22 μm diam. (x ̄ = 17.94 μm, n = 25) and conidial filament 1.9–3.7 μm wide (x ̄ = 2.5 μm, n = 20), 106.6–211.2 μm long (x ̄ = 138 μm, n = 30), tightly coiled 2.5–4.25 times, becoming loosely coiled in water, multi-septate, guttulate, hyaline, smooth-walled. Culture characteristics. Conidia germinated on PDA and produced germ tubes within 10 h. Colonies on PDA reaching 32 mm diam. after 30 days of incubation at 25 ° C. The colony is regularly circular in shape, with a convex surface; the central part is cracked, resembling a petal-like appearance, dark gray to brownish, with a pale brown margin. Reverse side is dark brown, with the margin varying from brown to white. Material examined. China • Yunnan Province, Pu’er City, Simao District (22°36'36"N, 101°0'14"E, 1189 m), on dead branches of C. arabica, 1 August 2024, M. Y. Han, (BG 21 = GMB -W 1485, holotype), ex-type GMBCC 2217, other living culture GMBCC 2218. GenBank number. GMBCC 2217 = ITS: PQ 737369, LSU: PX 308846, tef 1 - α: PX 314508, rpb 2: PX 314512 and GMBCC 2218 = ITS: PQ 737370, LSU: PX 308847, tef 1 - α: PX 314509, rpb 2: PX 314513. Notes. In the concatenated phylogenetic analysis, our strains [GMBCC 2217 (ex-type) and GMBCC 2218] of N. puerensis formed a sister branch to N. dehongensis (MFLUCC 18-1029) with 89 % ML / 0.99 PP statistical support (Fig. 1). Sequence comparisons between N. coffeae and N. dehongensis revealed greater divergence in the ITS region (34 / 933 bp; 3.6 %, no gap). Morphologically, our species resembles N. dehongensis in having macronematous and mononematous conidiophores, holoblastic conidiogenous cells with denticles, and helicoid, multi-septate, hyaline conidia (Dong et al. 2020). However, it differs from N. dehongensis in having slightly shorter conidiophores (138.8–211.7 µm vs. 120–250 µm) and conidia (106.6–211.2 µm vs. 145–210 µm), as well as narrower conidial diameters (15.2–22 µm vs. 20–25 µm) (Dong et al. 2020). In addition, conidia of N. puerensis are distinctly multi-septate, whereas those of N. dehongensis are indistinctly septate. The conidial filaments in our collections are more tightly coiled (2.5–4.25 times vs. 2.75–3.75 times), and conidiophores are usually unbranched, lacking the basal forking that is frequently observed in N. dehongensis. Moreover, conidiogenous cells of N. puerensis are terminal or intercalary, whereas those of N. dehongensis are mostly intercalary and sympodial. Thus, based on these morphological differences and molecular evidence, we propose that N. puerensis be recognized as a new species.