The Menyanthaceae are a relatively small family of aquatic and semi-aquatic flowering herbs with a center of diversity in Australia. The five genera comprising the family are Menyanthes, Fauria, Liparophyllum, Nymphoides, and Villarsia, and are often cultivated as ornamentals. Evolutionary patterns within the Menyanthaceae remain unclear despite previous studies utilizing anatomy, flavonoid, seed, and pollen morphology data. Parsimony analyses of rbcL sequences strongly resolve two major lineages within the family. These results portray a close relationship between the monotypic Menyanthes and Fauria, both of the Northern Hemisphere. The other clade depicts a strong alliance between Nymphoides, Villarsia, and Liparophyllum. The positioning of the monotypic Liparophyllum within a clade of Nymphoides species implies the present recognition of this Tasmanian-New Zealand endemic at the generic level may be unwarranted.

Key words: Menyanthaceae, phylogeny