Asteromidium Speg., Anal. Soc. cient. argent. 26(1): 66 (1888).
Index Fungorum number: IF 7263; Facesoffungi number: FoF 07126, 3 morphological species (Species Fungorum 2021), no molecular data available.
Mycelium immersed, branched, septate, hyaline. Sexual morph: Unknown. Asexual morph: Conidiomata acervular, subcuticular, separate or confluent, pulvinate to doliiform, at the base, composed of hyaline to pale brown, thin-walled textura angularis which extends laterally, finally with separate cells dispersed in a mucilaginous matrix to form the overlying wall; cuticle discolored and occasionally pseudoparenchymatous, walls adjacent to the upper epidermal wall also discolored; dehiscence irregular. Conidiogenous cells holoblastic, discrete, indeterminate, ± cylindrical, hyaline, smooth, with 1–2 sympodial proliferations, scars unthickened, flat, formed from the basal and lateral walls. Conidia cylindrical to fusoid, gently tapered at each end, apex obtuse, base truncate, thin-walled, guttulate to granular, hyaline, 3-septate (adapted from Sutton 1980; Quaedvlieg et al. 2016).
Type species: Asteromidium imperspicuum Speg.
Notes: Asteromidium is characterised by acervular conidiomata, holoblastic conidiogeneous cells, and cylindrical to fusoid conidia. The placement of Asteromidium in Mycosphaerellaceae is doubtful as molecular data is lacking. Asteromidium has to be recollected for further studies.