Neohelicomyces thailandicus

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

Index Fungorum number: IF557942; Facesoffungi number: FoF09287

Etymology: referring to Thailand, where the holotype was collected

Holotype: MFLU 11-1079

Saprobic on decaying, submerged wood in freshwater. Sexual morph: Undetermined. Asexual morph: Colonies superficial, effuse, gregarious, white. Mycelium mostly immersed in natural substratum, sparsely branched, hyaline to pale brown. Conidiophores 300–400 × 2.8–4.6 µm (x̄ = 345 × 3.6 µm, n = 5), macronematous, mononematous, sparsely branched, erect, slender, uneven in width, cylindrical, smooth-walled, brown to pale brown, septate, slightly constricted at septa, thin-walled. Conidiogenous cells 8–11 × 2–3.5 µm (x̄ = 9.7 × 2.8 µm, n = 10), holoblastic, mono- to polyblastic, discrete, determinate, arising in a whorl from pale brown, ampulliform-like or subcylindrical cells or directly from conidiophores near every septum, with each bearing 1–4 tiny conidiogenous loci, hyaline to pale brown, smooth-walled. Conidia solitary, dry, pleurogenous, helicoid, rounded at tip, 14–18 µm diam. and conidial filament 1.3–1.8 µm wide (x̄ = 15.5 × 1.6 µm, n = 10), 120–145 µm long, tightly coiled 3.75–4.25 times, indistinctly multi-septate, guttulate, hyaline, smooth-walled. (Description from Dong et al. 2020)

Culture characteristics: On PDA, colony circular, reaching 5 mm in 10 days at 25 °C, brown from above and below, surface rough, with dense mycelium, dry, edge entire.

Material examined: THAILAND, Chiang Rai Province, on submerged wood in a stream, 18 January 2010, H. Zhang, a47 (MFLU 11-1079, holotype), ex-type living culture MFLUCC 11-0005.

Notes: Neohelicomyces thailandicus clusters in Neohelicomyces with high bootstrap support. It can be distinguished from the other species by its conidiogenous cells arising from ampulliform-like or subcylindrical cells and conidiophores near the septa, with each bearing 1–4 tiny conidiogenous loci (Luo et al. 2017; Lu et al. 2018; Tibpromma et al. 2018; Crous et al. 2019).

Freshwater distribution: Thailand (Dong et al. 2020)