Native to eastern Asia, but introduced to Hawaii prior to 1870.
An annual weed that reproduces from seeds. It can be found in many locations including cultivated areas, pasture and rangeland, and along roadsides and in disturbed areas. Plants are very similar to “sensitive” varieties in this family that look similar, but this species’ leaves do not react to touching.
Mature plants can grow to about 3 feet in height, with multiple stems arising from the base and with some slight branching of the stems. The stem is thin but tough and fibrous. Leaves are on short stalks and are opposite along the stem. They are divided into from 15 to 30 pairs of leaflets, each of these long and narrow. The flowers are usually bright yellow, very small, and occur in small groups in the leaf axils. The seed pods are on short stalks and are narrow and curving and up to 1.5 inches long.
Characteristicts Important to Control:
Larger infestations of this weed can be controlled with a systemic or contact herbicide, and a pre-emergent herbicide will be effective in preventing seed germination.