Fungalpedia – Note 3095, Acrogenihelicosporium
Acrogenihelicosporium J. Ma, K.D. Hyde & Y.Z. Lu.
Citation when using this data: Jian Ma et al. 2024 – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Tubeufiaceae, Tubeufiales, Incertae sedis, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi.
Etymology: “Acrogeni-” refers to the acrogenous helicoid conidia of this fungus. “-helicosporium” refers to the genus morphologically similar to the helicosporous asexual morph of Helicosporium.
Saprobic on dead wood. Sexual morph undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on natural substrate superficial, effuse, gregarious, cotton-like, with masses of crowded, glistening conidia, white or pale green to yellow-green. Mycelium partly immersed, partly superficial, composed of hyaline to pale brown, branched, septate, guttulate, smooth hyphae. Conidiophores macronematous, mononematous, erect, cylindrical, straight or slightly flexuous, rarely branched, septate, slightly constricted at septa, pale brown to brown, smooth-walled, thick-walled. Conidiogenous cells holoblastic, monoblastic or polyblastic, integrated or discrete, terminal or intercalary, denticulate, subhyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, tapering towards the rounded ends, developing on tooth-like or bladder-like protrusion, becoming loosely coiled in water, aseptate, guttulate, hyaline, smooth-walled.
Notes: Acrogenihelicosporium exhibits morphological similarities with Acanthohelicospora and Helicosporium, but is phylogenetically distinct from these genera, indicating that it is a novel helicosporous genus within Tubeufiaceae (Tubeufiales) (Lu et al. 2017a, 2018b; Xiao et al. 2023). Acrogenihelicosporium can be distinguished from Acanthohelicospora and Helicosporium by its curved conidiophores and the presence of abundantly acropleurogenous helicoid conidia. In contrast, Acanthohelicospora species feature stiff and bristle-like, slightly flexuous conidiophores, and large, tightly coiled, pleurogenous conidia (Lu et al. 2017a), while Helicosporium displays similar conidiophores and rarely exhibits acrogenous helicoid conidia (Xiao et al. 2023). Furthermore, Acrogenihelicosporium species show a sister phylogenetic relationship to Tubeufiaceae sp. (CBS 284.54), supported by maximum bootstrap support (ML = 100%, PP = 1.00), as depicted in Fig. 4 (Ma J et al. 2024). However, the morphological characteristics of CBS 284.54 remain undescribed (Tsui and Berbee 2006), indicating its distinction from the species under investigation in our phylogenetic analysis. Therefore, Acrogenihelicosporium gen. nov. is described and introduced in this study to accommodate four species: A. abundatum, A. aquaticum, A. guizhouense, and A. viridisporum.
Type species: Acrogenihelicosporium abundatum J. Ma, K.D. Hyde & Y.Z. Lu.
Other accepted species: Species Fungorum – search Acrogenihelicosporium.
Figure 1 – Acrogenihelicosporium abundatum (HKAS 128932, holotype). a, b Colonies on submerged decaying wood. c–e Conidiophores, conidiogenous cells and conidia. f–i Conidiogenous cells. k–m Conidia. n, o Colonies on PDA from above and below. Scale bars: c–e =50 µm, f = 20 µm, g–m = 10 µm
References
Entry by
Jian Ma, School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang 550003, P.R. China, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand.
Published online 3 September 2026