Mycosphaerella Johanson (1884) is a dothideaceous genus that contains a large number of described species characterized by aparaphysate, mostly unilocular ascomata, ventricose ovoid or oblong to elongate or somewhat clavate bitunicate asci and l-septate usually hyaline, fusiform to ovoid, obovoid or elongate ascospores. A summary of the turbulent history of the name Mycosphaerella Johanson and its earlier name Sphaerella (Fries) Rabenhorst (1856) has been provided by Holm (1975) and Corlett (1988). Sphaerella, although it had been used by mycologists for decades, had to be discarded because the name had been earlier applied to a group of algae, i.e., Sphaerella Sommerfelt (1824). To complicate matters, Sphaerella Cesati & de Notaris (1863) was proposed and it is now considered a synonym of Mycosphaerella. Finally, and not relevant to these fungi, was the publication of Sphaerella Bubani (1901) for a genus of the Poaceae.