Amorpha fruticosa is a species of flowering plant in the legume family known by several common names, including desert false indigo and bastard indigobush. It is found throughout eastern Canada, northern Mexico, and most of the continental United States. In California it is native to the southwestern part of the state with scattered occurrences in the central valley. A. fruticosa grows as a hairy, thornless shrub which can reach 3 to 4 meters in height and spread to twice that in width. It is somewhat variable in morphology. The leaves are made up of many hairy, oval-shaped, spine-tipped leaflets. The flower cluster is a spike-shaped raceme of many flowers, each with a single purple petal and ten protruding stamens with yellow anthers. The fruit is a legume pod containing one or two seeds.

This plant likes moist (but not saturated) areas, and will spread wherever it finds suitable moisture. It is loosely branched and can become leggy with age; it needs plenty of room to spread out. Its spreading tendency and fibrous root system make it useful for bank stabilization. It is winter deciduous so will be less attractive for several months out of the year. It is the host plant for the Southern Dogface butterfly.