Digitodesmium P.M. Kirk, Trans. Br. mycol. Soc. 77(2): 284 (1981).
Index Fungorum number: IF 8029; Facesoffungi number: FoF 01264, 7 morphological species (Species Fungorum 2022), 2 species with molecular data.
Saprobic on rotten wood. Sexual morph: Unknown. Asexual morph: Hyphomycetous. Conidiomata sporodochial, scattered, punctiform, pulvinate, pale brown to brown, immersed mycelium, pale brown, smooth, septate, branched. Conidiophores semi-macronematous, mononematous, fasciculate, composed of very pale brown, smooth, septate, moniliform hyphae. Conidiogenous cells holoblastic, monoblastic, integrated, terminal, determinate, globose to doliiform, minutely cicatrized. Conidia crogenous, solitary, euseptate, dry, digitate, cheiroid, wide at the base, slightly divergent rows, occasionally with a hyaline gelatinous cap at the apex (adapted from Kirk 1981 and Boonmee et al. 2016).
Type species: Digitodesmium elegans P.M. Kirk
Notes: Digitodesmium was introduced by Kirk (1981) with D. elegans as type species. Digitodesmium is characterised by sporodochial, scattered, punctiform, pulvinate, pale brown to brown conidiomata, holoblastic, monoblastic conidiogenous cells and crogenous, solitary, euseptate conidia. Digitodesmium is unique and differs from other genera in having digitate conidia and moniliform conidiophores (Kirk 1981; Boonmee et al. 2016). Tsui et al. (2006) mentioned that Digitodesmium might be a synonym of Dictyosporium as Digitodesmium clustered within Dictyosporium in their phylogenetic analysis but with low statistical support. This observation was also reported by Cai et al. (2008). Digitodesmium differs from Dictyosporium in having divergent conidial arms (Tsui et al. 2006; Cai et al. 2008). Boonmee et al. (2016) accepted Digitodesmium as a distinct genus in Dictyosporiaceae based on phylogenetic analyses and mentioned the moniliform conidiophores as a significant character to delineate species of Digitodesmium. Dong et al. (2020) reported that three freshwater taxa namely Digitodesmium bambusicola, D. heptasporum and D. recurvum fit well within the generic concept of Digitodesmium in producing divergent conidial arms. Digitodesmium is morphologically and phylogenetically a distinct genus in Dictyosporiaceae. Molecular markers available for Digitodesmium are ITS, LSU, SSU and TEF-1.