Origin:
Native to tropical America, now distributed widely in the U.S.
Biology:
Mature plant is well branched, and forms a mat on the soil surface that may reach a diameter of 20 inches. In landscape plantings the stems may twine up and over the tops of other plants. Seeds germinate in late spring and the plant matures in late summer.
Identification:
Generally low-growing and mat-forming, with thin, multi-branching stems. Leaves occur in whorls around the stem, in groups of 3 to 6 leaves, with tiny white flowers occurring in the axils of the leaves. Leaves are thin and up to 1 inch long, narrowly spatulate shaped. Flowers are small and inconspicuous, blooming from mid-summmer to fall, and are in clusters of 2 to 5 on short stems arising from the bases of the leaves. Flowers are whitish.
Characteristicts Important to Control:
Commonly infests landscaped areas, gardens, low groundcovers, lawns, orchards and vineyards, but less of a problem in cultivated annual crops. Prefers moist, exposed, disturbed wetland margins and roadsides. Germinates later than most other weeds, and this along with its low growth habit may allow it to be missed in control programs.