This weed is troublesome to so many homeowners that it is worthy of being brought to your attention every year at this time. Lawn burweed (Soliva pterosperma), more commonly called sticker weed becasue of its cluster of tiny seeds with spines. At maturity they can stick into tender flesh of bare feet, knees, hands, or whatever parts of the body that may come in contact with them.
Lawn burweed 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 tiny carrot leaves. The real identifier is the small, rosette button fruit clusters that form down in the leaf axils once the plant reaches a reproductive stage. At maturity, usually late spring and into summer, is when we endure their pain from the dried sharp spines.
Lawn burnweed should not to be confused with Southern Sandbur (Cenchrus echinatus) a summer annual grassy weed with seedheads having sharp spines or burs.
If you did not apply a pre-emergent herbicide earlier this fall to control winter annual weeds and you had lawn burweed in your lawn last summer, then you most likely have them again now. You will have to endure their painful spines for another summer unless you take action soon to control them.
Once the fruiting clusters have formed you can eliminate the weed, but the tiny spines and seed will remain to inflict pain for another summer.
Extension publications Weed Control Guidelines for Mississippi and Establish and Manage Your Home Lawn provide lists of several good post-emergent herbicide choices that will control this weed along with most other winter annual weed species but timing is critical.
Published February 7, 2011
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. wwells@ext.msstate.edu