South Dakota Native Plant Research
Fabaceae : Amorpha fruticosa

Fabaceae : Amorpha fruticosa


Download Seedling (508 KB)

Download Plant along the Sheyenne River (1.1 MB)

Download Developing fruit (1.5 MB)

Family Name


Common Name

False indigo

Native American Name

Lakota: ziŋtkála tȟačháŋ


Amorpha fruticosa is a deciduous perennial shrub, which has 1 to several stems growing from 1 m to 3.5 m in height, often branched, forming a bushy top. The alternate, pinnately compound leaves are stipulate (caduceus, narrowly linear 2-4 mm in length) 10 – 30 cm long with 4 – 15 pairs of emarginate leaflets. The inflorescences are solitary to clusters of densely flowered racemes 5-20 cm in length that bloom from June to August. The 5-merous calyx is fused forming a tube 2-3 mm long with broadly rounded to triangular lobes extending about 0.5 mm. The reddish-purple petals form a tube 5-6 mm long that encloses the stamens and pistil. There are 10 stamens 6-8 mm long and united at the base, with bright yellow anthers. The single pistil matures into a legume 5-7 mm by 2-3 mm. False indigo is commonly found along moist stream banks, in the open or in open woods.

Additional Notes

False indigo is not generally browsed. Northern Plains Indians used its straight branches for arrow shafts. The plant contains some indigo pigment and can be used to make a blue dye. Amorpha fruticosa is a very hardy plant, tolerating temperatures down to about -25°c when fully dormant. A. fruticosa attracts bees and butterflies and is resistant to many insect pests.

Horticulture Notes

Seed Collection: Seeds mature in the autumn and can be harvested when the pods dry.

Germination: Pre-soak seeds for 12 hours in warm water and then sow early spring, or chip a small hole in the seed coat to let water enter. Be careful not to damage the fleshy cotyledons within the seed. Vegetative Propagation: Cuttings of greenwood shoots can be rooted in spring and, early summer. Cuttings of mature wood of the current seasons growth can be mad in autumn and rooted in a sheltered position outdoors becoming viable the following summer. Suckers can be dug in spring just before new growth begins.

Soils: a light well-drained sandy soil

Light: Full sun to light shade

Fabaceae : Amorpha fruticosa