Cabombaceae is closely related with Nymphaeaceae and often united with it. However, recent molecular phylogenetic research defends its segregation (Taylor 2008, APGIII 2009).
A single genus, Cabomba, has been recorded in the wild in Belgium.
APG III (2009) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants. APG III. Bot. J. Linn. Soc. 161(2): 105-121.
Taylor D.W. (2008) Phylogenetic Analysis of Cabombaceae and Nymphaeaceae Based on Vegetative and Leaf Architectural Characters. Taxon 57(4): 1082-1095.