The family Dothideaceae, within the order Dothideales, is a group of fungi commonly referred to as bitunicate ascomycetes due to their distinctive double-walled asci. Members of this family are typically saprobic, living on decaying plant material, though some are also plant pathogens. They produce their spores in specialized fruiting bodies called ascocarps, which are often dark and flask-shaped, and their ascospores can vary widely in shape and septation. Dothideaceae fungi are cosmopolitan, occurring in diverse terrestrial habitats, and play important ecological roles in nutrient cycling and, in some cases, in causing plant diseases.