Within Botryosphaeriales the asexual morphs are more frequently encountered than the sexual morphs. However, within a family or even within a genus the range of morphologies of the asexual morphs is so great that asexual morph morphology is of little value to define the families. For example, within Botryosphaeriaceae conidia can be thin-walled and hyaline, or thick-walled and coloured. Even within a genus, such as Diplodia, conidia can be either aseptate or 1-septate. Therefore, we attempted to define families according to morphology of the sexual morphs, even if such morphs are uncommon and are not known for all genera within a family. On this basis, six morphological groups could be distinguished. A primary distinction was based on gross morphology of the ascostromata as either multiloculate or uniloculate. In Aplosporellaceae, Melanopsaceae and Planistromellaceae the ascostromata are multiloculate, while in Phyllostictaceae and Saccharataceae the ascostromata are uniloculate. Most of the genera in Botryosphaeriaceae have ascostromata that are clearly uniloculate, but in Botryosphaeria and Neofusicoccum the ascostromata are often aggregated in large clusters that can give the impression that they are multiloculate. In fact, ascostromata in Botryosphaeriaceae have been referred to as uni- to multiloculate (Slippers et al. 2004; Liu et al. 2012; Phillips et al. 2013). However, even though the aggregations are united on a common basal stroma, their uniloculate origin can be seen in sections cut through the aggregates. Furthermore, within these two genera the ascostromata are most frequently found as individuals.