Perennials, 0-150(-200) cm, usually rhizomatous or stoloni-ferous. Stem bases hard, some-times ± woody. Leaves: blades of mid cauline oblong to lanceolate, (3-)6-40 × 2-15 cm, bases auriculate, auricles straight or curved, rounded, margins usually pinnately lobed, lobes ± deltate, not constricted at bases, terminals usually larger than laterals, dentate or entire. Peduncles sessile- or stipitate-glandular. Involucres 10-17+ mm. Phyllaries sessile- or stipitate-glandular. Corollas: ligules ± equaling tubes. Cypselae dark brown, oblanceoloid to ellipsoid, 2.5-3.5 mm, ribs 4-5(+) on each face, faces transversely rugulose to tuberculate across and between ribs; pappi 8-14 mm. 2n = 36, 54. Sonchus arvensis is introduced in temperate regions of all continents. Plants of the species prefer relatively cooler, moister climates and are more abundant in the northern part of North America.