Sesbania is a genus of flowering plants in the pea family, Fabaceae, and the only genus found in tribe Sesbanieae. Riverhemp is a common name for plants in this genus. Notable species include the rattlebox (Sesbania punicea), spiny sesbania (Sesbania bispinosa), and Sesbania sesban, which is used in cooking. Plants of this genus, some of which are aquatic, can be used in alley cropping to increase the soil's nitrogen content. The species of rhizobia responsible for nitrogen fixation in Sesbania rostrata is Azorhizobium caulinodans. Some 60 species are currently accepted, with about 39 still unresolved. The genus is native to tropical and subtropical regions around the world, in the Americas from the southern United States to northern Argentina, in sub-Saharan Africa, in southern Asia, and in New Guinea, Australia, and the Pacific. The largest number of species are found in Africa, and the remainder in Australia, Hawaii, and Asia.

Fossil record

Fossil seed pods from the upper Oligocene resembling Sesbania have been found in the Hungarian locality of Eger Wind-brickyard. The fossil species grew in a swampy and riparian environment.

List of species

60 species are accepted, organized into three sections:

Section Glottidium (Desvaux) Lavin

Section Daubentonia (DC.) Bentham

Section Sesbania Adans.

Incertae Sedis

Phylogeny

Modern molecular phylogenetics suggest the following relationships between the species of Sesbania: