PERENNIAL SOWTHISTLE, Sonchus oleraceus L. 1, lower part of plant; 2, upper part of stem with flowers; 3, seed. Perennial, reproducing by seed and creeping roots. Roots may penetrate soil to a depth of several feet and spread horizontally, producing shoots from buds on the roots. Stems smooth, 3 to 7 feet (0.9 to 2 m) tall, erect, with a milky juice and a whitish bloom on the surface. Leaves 4 to 8 inches (10 to 20 cm) long, alternate, irregularly toothed, lobed, edges spiny. Flower heads about 1112 inches (3.8 cm) across, composed of deep yellow ray flowers. Seed dark reddish-brown, about 1/8 inch (3 mm) long, slightly flattened, 5- to 7-ribbed with smaller cross wrinkles and with a tuft of hair on one end that is easily broken off. Found in cultivated fields, pastures, and wasteland. It is not easily destroyed and becomes a serious problem in grain and row crops.