Lawn burrweed, also known as spurweed, is a very low-growing winter annual weed that closely resembles parsley-piert and knawel. It is freely branched and usually does not root at the nodes. The leaves are oppositely arranged and highly divided into little leaf segments. Flowers are small (1/4 inch or less), broad, and inconspicuous. The seeds have sharp spines, hence the common name. Lawn burrweed is commonly found in turfgrass systems. Infestations are increasing in North Carolina, particularly in the southern Coastal Plain and Piedmont.
Winter annual broadleaf weeds germinate in the fall or winter and grow during any warm weather, which may occur in the winter, but otherwise remain somewhat dormant during the winter. They resume growth and produce seed in the spring and die as temperatures increase in late spring and early summer. They quickly invade thin turf areas especially where there is good soil moisture. Shade may also encourage growth. Many have a prostrate growth habit and are not affected by mowing. A dense, vigorous turf is the best way to reduce the encroachment of winter annual weeds. First, select adapted turfgrass cultivars for your area and then properly fertilize, mow, and water to encourage dense growth.
Growth Season/Life Cycle
winter annual weed
three-lobed with each lobe again divided into lobes
upper/lower surface; sparsely hairy