Phylogenetic systematics and biogeography of the pantropical genus Sesbania (Leguminosae)

Abstract—The pantropical genus Sesbania (Leguminosae) comprises approximately 85 species and 34 infraspecific taxa. This genus is unusual ecologically in its predilection for wetlands, and morphologically distinctive among legumes, yet has never been comprehensively investigated for the phylogenetic integrity of its subgeneric classification. We subjected a broad sampling of Sesbania species to phylogenetic analysis using both nuclear and plastid DNA sequence data. The resulting phylogenies support the monophyly of Sesbania and two constituent subclades, one represented by the New World endemic sections Daubentonia, Daubentoniopsis and Glottidium, and the second comprising the pantropically distributed section Sesbania and former subgenera Pterosesbania and Agati. The species-rich section Sesbania is paraphyletic with respect to subg. Agati and Pterosesbania, while sect. Daubentonia is paraphyletic with respect to sect. Daubentoniopsis. Based on these results we revise the sectional cla...