A native of South America, now a common weed in much of California, where it favors habitats of high moisture along ditch banks or roadsides, as well as stream beds that dry up in the summer.
An annual weed that grows rapidly to over 6 feet in height, usually with a single stem that may have small numbers of branches at its upper length. Plants are upright and tend to be fairly spindly and open looking.
Reproduction is from seeds.
Mature plants are very tall, with a single main stem that is squared and is covered with short, coarse hairs. The lower parts of the stem may have very few hairs.
Flowers are borne in dense, tubular clusters at the ends of the stems, each cluster being up to 1.5 inches long, but with many clusters together to form a flat-topped grouping. Individual flowers are tiny, pink to purple, and tube shaped with 5 lobes, growing out from the cluster. Flowers emerge from the base of the cluster first, so the newest flowers are at the top.
Characteristicts Important to Control:
An annual reproducing only from seeds. Individual plants can easily be removed by hand.