Origin:
Native to tropical America and introduced into the United States, where it now can be found from South Carolina and Florida west to New Mexico, in Illinois and in Hawaii.
Biology:
An annual weed or, in warm climates, a short-lived perennial that grows in a mat-like, spreading habit. Reproduction is from seeds, but the spread of the plant is encouraged by its ability to root at the nodes where the stems contact the soil. A problem in turf and landscape, along roadsides and other disturbed sites, and in pastures and fields.
Identification:
Plants overall are short and spreading, although individual stems may grow erect. Stems and leaves are sparsely covered with short hairs on the dark green foliage. The leaves are alternate, oval to arrowhead shaped with pointed tips, toothed margins, and short petioles. The small yellow flowers occur at the ends of the stems, and have 8 to 10 open ray flowers and a small area of disc flowers.
Characteristicts Important to Control:
Physical removal of single plants is effective but relies on removal of all the stems. When found in turf most members of the sunflower family can be effectively controlled with a selective broadleaf herbicide. Prevention of seed germination can be accomplished with a pre-emergent herbicide. In turf it does best when turf is not mowed regularly.
