Tubeufiales » Tubeufiaceae » Neohelicomyces

Neohelicomyces dehongensis

Neohelicomyces dehongensis H. Zhang, W. Dong & K.D. Hyde

Index Fungorum number: IF557941; Facesoffungi number: FoF09286

Etymology: referring to Dehong, where the holotype was collected

Holotype: MFLU 18-1168


Saprobic on decaying, submerged wood in freshwater. Sexual morph: Undetermined. Asexual morph: Colonies superficial, effuse, gregarious, white. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, branched hyphae, with mass of crowded, glistening conidia. Conidiophores 120–250 × 3.3–3.9 µm ( = 180 × 3.5 µm, n = 10), macronematous, mononematous, unbranched or loosely branched, branches often forked close to the base, upper part frequently sterile, erect, cylindrical, pale brown, septate, slightly constricted at septa, guttulate, smooth-walled, thin-walled. Conidiogenous cells 12–17.5 × 3–4 µm ( = 14.5 × 3.5 µm, n = 20), holoblastic, mono- to polyblastic, integrated, sympodial, intercalary, cylindrical, with denticles, hyaline to pale brown, smooth-walled. Conidia solitary, dry, pleurogenous, helicoid, rounded at tip, 20–25 µm diam. and conidial filament 2.2–4 µm wide ( = 22 × 3 µm, n = 15), 145–210 µm long, tightly coiled 2.75–3.75 times, becoming loosely coiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled. (Description from Dong et al. 2020)


Culture characteristics: On PDA, colony circular, reaching 5 mm in 25 days at 25 °C, brown from above and below, surface rough, with dense mycelium, dry, edge entire.


Material examined: CHINA, Yunnan Province, Dehong, on submerged wood in a stream, 25 November 2017, G.N. Wang, H3C-1 (MFLU 18-1168, holotype), ex-type living culture MFLUCC 18-1029; ibid., H3C-2 (HKAS 101728, isotype), ex-type living culture KUMCC 18-0078.


Notes: Neohelicomyces dehongensis clusters with three strains of N. pallidus (Ces.) Y.Z. Lu & K.D. Hyde (Fig. 129). Neohelicomyces dehongensis differs from N. pallidus in having larger conidia (20–25 µm diam. vs. 10–16 μm diam.) and wider conidial filament (2.2–4 µm vs. 1–2 µm) (Linder 1929; Zhao et al. 2007). Neohelicomyces pallidus (UAMH 10535) clusters in the same clade with N. pandanicola Tibpromma & K.D. Hyde, which is apart from the other three strains of N. pallidus. This indicates that N. pallidus UAMH 10535 is a distinct species. However, we do not change its status as there is a lack of morphology. (Notes from Dong et al. 2020)


Freshwater distribution: China (Dong et al. 2020)