Tubeufia abundata Y.Z. Lu, J.C. Kang & K.D. Hyde
Index Fungorum number: IF 554895; Facesoffungi number: FoF 04749
Etymology: “abundata” referring to the abundant conidiophores.
Holotype: MFLU 17–1213
Saprobic on decaying wood in a freshwater stream. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, abundant, cylindrical, branched, septate, 55–225 μm long, 5–7 μm wide, hyaline to brown, smooth-walled. Conidiogenous cells comprising two types: (1) holoblastic, monoblastic, integrated, sympodial, terminal, cylindrical, truncate at apex after conidial secession, 12–22 μm long, 4–5 μm wide, hyaline to pale brown, smooth-walled; (2) holoblastic, monoblastic, integrated, sympodial, intercalary, cylindrical, with denticles, 8.5–11 μm long, 5–7 μm wide, pale brown to brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 25–40 μm diam. and conidial filament 3.5–4.5 μm wide (x̄ = 32 × 4 μm, n = 20), 180–210 μm long, tightly coiled 2¼–3 times, becoming loosely coiled in water, multi-septate, up to 26-septate, guttulate, hyaline, smooth-walled. (Lu et al. 2018)
Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 12 h. Colonies growing on PDA, circular, with a center slight umbonate surface, edge entire, reaching 39 mm in one month at 28 °C, pale brown to brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.
Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on submerged decaying wood in a freshwater stream, 25 March 2017, Yong-Zhong Lu, CR43 (MFLU 17–1213, holotype; HKAS 100779, isotype), ex-type living culture, MFLUCC 17–2024.
Notes: Tubeufia abundata can be easily distinguished from other helicosporous hyphomycetes by its abundant conidiophores with non-hygroscopic helicoid conidia. Most conidia of T. abundata are acrogenous on the terminal cylindrical conidiogenous cells which are truncate at apex after conidial secession, but a few of them are pleurogenous and develop from intercalary conidiogenous cells with tiny tooth-like protrusions arising laterally from conidiophores. Phylogenetically, T. abundata clusters within Tubeufia with high bootstrap support and support that it is a distinct species (Lu et al. 2018).
Freshwater distribution: Thailand (Lu et al. 2018)