Lawn burweed in New Zealand turfgrass has developed resistance to clopyralid herbicides due to continuous use. The resistant weed is also less affected by dicamba, MCPA, and picloram, but not mecoprop. The resistant plants look different from the susceptible ones, with fewer leaf lobes and larger size. They also have larger leaves and roots. This resistance reduces options for controlling the weed with chemicals, so other methods like promoting turfgrass growth may be necessary.