Perennial sowthistle is a creeping-root perennial that reproduces by a fleshy root or by wind-dispersed seeds. The flower is bright yellow and resembles dandelion flowers, although this plant grows much taller, usually 2-5 feet. The leaves have winged stalks and prickles on the margins. Perennial sowthistle has a milky sap, evident when broken or scraped. In Teton County this plant rarely forms monocultures and is often scattered along the levee system. For advice on controlling this invader or for a free consultation of your Teton County residence, please contact Teton County Weed & Pest District at 733-8419.