The Datiscaceae are a family of Dicotyledonous plants, containing two species of the genus Datisca. Two other genera, Octomeles and Tetrameles, are now classified in the family Tetramelaceae. Datiscaceae are large herbaceous plants, with alternate and pinnate leaves. They are actinorhizal plants, that host nitrogen-fixing bacteria in their roots, and are the only ones that are not a tree or shrub, although non-actinorrhizal plants also fix nitrogen, like legumes.