A native of tropical Africa, but cultivated as a garden plant and introduced to the United States. It can be found from North Carolina south to Florida and west to Texas, commonly in Hawaii, and in the West Indies.
A very tall-growing annual that reproduces from seeds, this attractive weed is common along roadsides and waste areas in some locations. It may also be found in cultivated habitats, pastures, and open fields.
The mature plants may grow to 6 feet in height, with single to multiple straight, erect, fibrous stems that are covered with soft hairs. There may be some branching of the stems at the upper end. The majority of the foliage is along the lower areas of the stems, with oval to arrowhead shaped leaves that are 5 inches long. The margins of the leaves are scalloped or deeply dentate, and the leaves are opposite or somewhat whorled. The flower clusters grow as round golf ball-sized clumps along the upper stems. These spiny balls produce orange to scarlet flowers that protrude from the sides of the green cluster to about 1.5 inches long. Below each flower head there are 2 or more small leaves.
Characteristicts Important to Control:
Individual plants may be physically removed. In a widespread infestation plants may be killed with a non-selective herbicide, but dead plants can still remain for long periods and may need to removed as well.