Senna, the sennas, is a large genus of flowering plants in the legume family (Fabaceae, subfamily Caesalpinioideae,^[2] tribe Cassieae). This diverse genus is native throughout the tropics, with a small number of species in temperate regions. The number of species is estimated to be from about 260^[3] to 350.^[4] The type species for the genus is Senna alexandrina. About 50 species of Senna are known in cultivation.^[