Any of several leguminous North American shrubs of the genus Amorpha, having long spiked clusters of purple flowers and hairy pinnate leaves. Also (in form Amorpha): the genus itself.
Valid publication of the genus name: Linnaeus Species plantarum II. (1753) 713.
Mid 18th century; earliest use found in John Hill (bap. 1714, d. 1775), physician and actor. From scientific Latin Amorpha, genus name from ancient Greek ἄμορϕος shapeless + scientific Latin -a, so called because the flowers have only one petal.