Citation: Pem D et al. (2019) Mycosphere Notes 275-324: A morphotaxonomic revision and typification of obscure Dothideomycetes genera (incertae sedis). Mycosphere 10(1), 1115–1246
Asteronia (Sacc.) Henn., Hedwigia 34: 104 (1895)
≡ Asterina subgen. Asteronia Sacc., Syll. fung. (Abellini) 1: 47 (1882)
Parasitic or pathogenic on living leaves of Sweetia sp. Sexual morph: Colonies forming darkened regions on the underside of leaves, similar to a “sooty mold”. Ascomata gregarious, solitary or some scattered, superficial, globose, subglobose to ovate, subcoriaceous, brown to black-brown, with an indistinct ostiole. Peridium comprising one layer of black-brown isodiametric cells of textura angularis. Hamathecium not apparent. Asci 8-spored, bitunicate, oblong to broadly cylindrical, with a short indistinct pedicellate or sometime sessile, apically rounded and thickened, with an indistinct ocular chamber. Ascospores tri to multiseriate, guttulate, thin-walled, straight or slightly curved, fusoid-ellipsoidal, widest in the middle part of the apical cell, with broadly rounded apex and tapering to a narrowly rounded base, hyaline, 1-septate, septum nearly central but nearer to apex, rough-walled. Asexual morph: Undetermined.
Type species – Asteronia sweetiae Henn.
Notes – Asteronia was introduced as a monotypic genus with Asteronia sweetiae as the type species. Consequently, Hennings (1908) added A. lauraceae Henn. to the genus. Currently, two species are accommodated in the genus. There is no report of the asexual morph. The genus Asteronia was previously placed in Microthyriaceae by Lumbsch & Hundorf (2010). Later, Hyde et al. (2013) transferred the genus to Dothideomycetes genera incertae sedis. The genus is characterised by an ascoma that are subglobose and gregarious, and 8-spored asci that are bitunicate with fusoid-ellipsoidal ascospores. Cultures and sequences are unavailable. We re-examined the type specimen of Asteronia sweetiae. The globose ostiolate ascomata formed on black mycelium and lack of flattened thyriothecia indicate that the genus Asteronia does not belong to Microthyriaceae, but is probably a member of Perisporiopsidaceae. The fact that the morphological characters of the genus Asteronia fits well within the species concept of Perisporiopsidaceae in having superficial ascomata with surrounding mycelia, and ellipsoidal oblong, 1 septate, hyaline ascospores, we transfer the genus Asteronia to the family Perisporiopsidaceae.