Low-growing freely branched winter annual. Leaves opposite, sparsely hairy and twice divided into narrow segments or lobes. Flowers small and inconspicuous. Fruits clustered in leaf axils having sharp spines that can cause injury to humans. Reproduces by seed. Generally found in the Coastal plain and Piedmont Regions of most southern states, North Carolina south into Florida, and west to Texas. Also occurs in South America and Europe.