The Rhynchosia senna complex is treated as having four species: R. senna and R. azuaensis, confined to South America; R. prostrata, confined to North America; and R. texana, occurring in both North and South America. One new combination, Rhynchosia azuaensis (Grear) B.L. Turner, stat. nov. is proposed. A key to the taxa is provided, along with maps showing their distribution.