Amorpha is a genus of plants in the pea family, Fabaceae. The name Amorpha means ‘deformed’ or ‘without form’ in Greek and was given because flowers of this genus only have one petal, unlike the usual ‘pear-shaped’ flowers of the Faboideae subfamily.
Amorpha is missing the wing and keel petals. The desert false indigo or indigo bush (Amorpha fruticosa), is a shrub that grows from 3 m to 5 m tall.
Amorpha species are used as food plants by the larvae of some Lepidoptera species including Schinia lucens, which feeds exclusively on the genus.
Amorphol, a rotenoid biocide, can be isolated from plants of the genus Amorpha.