Lawn burweed (Soliva pterosperma), more commonly called sticker weed, is best described as a low-growing, freely branched winter annual having leaves that are twice divided into narrow segments or lobes similar to the appearance of carrot leaves, but much smaller.
The real identifier is once the plant reaches a reproductive stage the small fruit clusters and small rosette buttons begin to form down in the leaf axils. At the tip of each seed, within the cluster, is a tiny spine that eventually dries at maturity. What's left causes you pain as they stick into tender flesh of bare feet, knees, hands, or whatever parts of the body that may come in contact with them.
If you had lawn burweed in your lawn last summer and did not apply a pre-emergent herbicide earlier this fall, then you most likely will have them again and will have to endure their painful spines again this summer.
Once the fruiting clusters have formed and produced the tiny seeds and spines, killing the plants will only eliminate the weeds. The tiny spines and seed will remain to inflict pain for another summer. Extension publication "Weed Control Guidelines for Mississippi" provides a list of several good post-emergent herbicide choices (atrazine, 2,4-D, dicamba, metsulfuron, chlorsulfuron, etc.) that will control this weed along with most other winter annual weed species, but timing is critical.
Published February 11, 2008
Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. email@example.com