Cercosperma G. Arnaud ex B. Sutton & Hodges, Nova Hedwigia 35(4): 798 (1983) .
Index Fungorum number: IF 7544; Facesoffungi number: FoF 08589, 2 morphological species (Species Fungorum 2021), molecular data unavailable.
Saprobic on host. Asexual morph: Mycelium mostly superficial, composed of thick-walled, branched, brown, anastomosing, smooth hyphae; hyphopodia and setae absent. Conidiophores micro- to semi-macronematous, mononematous, erect, pale brown, often with a single short lateral branch at base. Conidiogenous cells holoblastic, determinate, integrated or discrete, terminal on the main axes or lateral branches, pale brown, smooth, with flattened apex. Conidia solitary, dry, acrogenous, straight to curved, tapered towards apex, truncate at base, distoseptate, alternate septa thickened, lumina reduced, smooth, pale brown. Sexual morph: Unknown (Adapted from Sutton and Hodges 1981).
Type species: Cercosperma arnaudii B. Sutton & Hodges
Notes: Cercosperma was introduced by Arnaud (1981) with C. arnaudii as type species and validated by Sutton and Hodges (1983). Cercosperma is characterized by micro- to semi-macronematous, mononematous, pale brown conidiophores, dry, acrogenous, pale brown distoseptate conidia. The taxonomic position of Cercosperma is still unresolved due to lack of molecular data. Cercosperma is similar to Ceratophorum, which is another genus whose taxonomic placement is also uncertain. Sutton and Hodges (1983) also discussed the similarities of Cercosperma to Sporidesmium in having almost similar conidia or extremely short conidiophores and conidiogeneous cells. Cercosperma however, differs from Sporidesmium in having very short conidiophores with distoseptate conidia. The two species of Cercosperma is differentiated based on conidial dimensions and morphology. C. longispora has conidia which are longer and wider below the middle and tapered towards both end while those of C. arnaudii are widest at the truncate base and taper gradually to subacute apices. DNA sequence data is needed to resolve the taxonomic placement of Cercosperma. Cercosperma is currently treated as a doubtful genus in Mycosphaerellaceae. We could not loan the holotype of C. arnaudii. We illustrate the genus Cercosperma with a drawing of C. longispora, the second species of Cercosperma collected on Eucalyptus tereticornis (Myrtaceae) leaf litter from South India.