Genera 4, species ca. 370 (2 genera, 2 species in the flora).
The assemblage of genera comprising Thesiaceae received strong support from molecular phylogenetic analyses (J. P. Der and D. L. Nickrent 2008; Nickrent and M. A. García 2015). Buckleya is sister to the remaining genera, which are either endemic to or have their center of diversity in Africa. Because Buckleya occurs in eastern North America and Asia, the ancestor to the remaining genera apparently migrated to Africa prior to diversification.