-Plants (Kingdom Plantae)

-Vascular Plants (Phylum Tracheophyta)

-Flowering Plants (Subphylum Angiospermae)

-Dicots (Class Magnoliopsida)

-Legumes, Milkworts, and Allies (Order Fabales)

-Legumes (Family Fabaceae)

-Subfamily Faboideae

-Tribe Cassieae

-Subtribe Cassiinae

-Sennas (Genus Senna)

-Twin-flowered Cassia (Senna pallida)

This spreading little shrub comes from the southern United States, Central America, and northern parts of South America, where it is found usually in brushy plains and hillsides, either moist or dry, often in pineoak forest, and along roadsides. The flowers usually occur in pairs, hence the common name.