Curtail Herbicide translocates to the roots of stubborn perennial weeds, providing outstanding control of Canada thistle. In addition, Curtail also controls many annual broadleaf species, such as wild mustard, wild buckwheat, pigweed, lambsquarters, volunteer sunflower and more. Active Ingredients: Clopyralid 5.1% + 2,4-D - 39.0% EPA Signal Word - CAUTION / PRECAUCION