Phylogenetic analysis of Cabombaceae and Nymphaeaceae based on vegetative and leaf architectural characters

Vegetative and leaf architectural characters are used to assess the phylogenetic relationships of species of Cabombaceae and Nymphaeaceae. Twenty-eight species representing all eight genera and the five subgenera of Nymphaea are analyzed. These morphological analyses give robust support to other molecular and morphological analyses of the relationships of the two families. There is strong support for the two families to be monophyletic, and that Euryale and Victoria are closely related. Strict consensus analyses show that within the Nymphaeaceae, Nuphar is the first sister clade, followed by Barclaya and finally by a polytomy of Ondinea, Euryale-Victoria and Nymphaea. The relationships of Ondinea are uncertain, in part due to missing characters. Finally, the genera of each family are monophyletic. Each genus has a suite of distinctive vegetative characteristics that are used to make an identification key of the genera. Although the value of vegetative and leaf architectural characters is shown, inclusion of atypical leaves, for example some types of submerged leaves, results in less resolved or robust trees.