Sesbania tomentosa, also known as Oahu Riverhemp, is a species of flowering plant in the Fabaceae (pea) family, native to the Hawaiian Islands and the Necker and Nihoa Islands.
It occurs mainly in low scrublands and dry forests from sea level to 760 meters (2,500 feet). ATVs, forest fires, grazing, and competition from exotic species have destroyed their habitat on the main islands.
However, they are still widespread on Necker and Nihoa. At least 2, 000 species[1] grow in Nihoa, while much fewer in Necker. Oahu Riverhemp is very polymorphic and has excellent variations in shape and color. Plants growing in Nihoa have orange-red flowers and young, relatively hairless leaflets. Those growing in Necker have orange to salmon-colored flowers and very hairy leaves.
