They have sharp, thorny burs that poke into tires, paws, and bare feet. Puncture vines are weeds found in lawns, gardens and along roadsides over much of the West. They germinate in the spring and grow rapidly forming a dense low mat 5 – 15″ in diameter. They have yellow five petaled flowers in the leaf and open in the morning. Hoe or dig puncture vine plants when they are small, cutting below the crown to prevent regrowth. Get rid of the weed before it sets seed, treat with herbicidal soap in garden areas. Use a pre-emergence herbicide containing trifluralin or pendimethalin around lawn grasses and treat with a selective herbicide containing dicamba or methanearsonic acid.