Asterinella Theiss., Annls mycol. 10(2): 160 (1912).
Index Fungorum number: IF 411; Facesoffungi number: FoF 06729, 35 morphological species (Species Fungorum 2022), molecular data available for an unnamed species in the genus.
Biotrophic on the upper surface of leaves, superficial mycelium present, with hyphopodia. Sexual morph: Thryriothecia superficial, flattened, coriaceous, opening by splitting or cracking to form a pore. Upper wall comprising rows of cells, radiating from the central opening to the periphery, base poorly developed. Hamathecium of asci and sparse pseudoparaphyses inclined towards the central ostiole. Asci 8-spored, bitunicate, broadly cylindrical, apedicellate. Ascospores overlapping 2–3-seriate, light-brown to hyaline, 2-celled, constricted at the septum, the upper cell larger than the lower cell, ovoid, the upper cell with rough walls, lower cell smooth-walled. Asexual morph: Unknown (adapted from Wu et al. 2014).
Type species: Asterinella puiggarii (Speg.) Theiss.
Notes: Asterinella is characterised by superficial, flattened, coriaceous thyriothecia, bitunicate, broadly cylindrical, apedicellate asci and light-brown to hyaline, two-celled ascospores constricted at the septum. Müller and Arx (1962) and Lumbsch and Huhndorf (2010) treated Asterinella in Microthyriaceae. Asterinella resembles Maublancia but can be differentiated in the features of hyphopodia (Müller and Arx 1962; Wu et al. 2011). Wu et al. (2014) re-examined the holotype specimen of A. puiggarii from LPS and transferred Asterinella to Asterinaceae based on morphology. Asterinella has mucronate hyphopodia with a short branch of two cells while Maublancia has capitate hyphopodia with a single cell. Molecular data is lacking for Asterinella. Asterinella is currently a distinct genus in Asterinaceae but fresh collections with DNA sequence data are needed to confirm the taxonomic placement of the genus.