Sonchus ciliatus Lamarck; S. mairei H. Léveillé (1913), not H. Léveillé (1915).

Herbs 40-150 cm tall, annual or sometimes biennial. Stem below synflorescence simple or branched, glabrous. Basal and lower stem leaves with basal portion petiole-like and attenuate, mostly smaller than middle stem leaves, otherwise similar. Middle and upper stem leaves extremely variable, elliptic, oblanceolate, or lanceolate, 6-20 × 2-9 cm, almost entire to ± irregularly pinnatisect, soft, glabrous, adaxially dull green, base auriculately clasping with auricles usually acutely prostrate, margin ± coarsely spinulosely dentate, apex acute; lateral lobes triangular to elliptic, usually recurved, apex acute to acuminate; terminal lobe larger than others, broadly triangular, broadly hastate, or obovate-cordate. Synflorescence shortly corymbiform or racemiform, with few to several capitula. Capitula with many florets; peduncle 0.5-3(-5) cm, slender, glabrous, glandular hairy, or apically white tomentose. Involucre ± campanulate, 1-1.2 cm. Phyllaries glabrous or with few glandular hairs, apex ± obtuse; outer phyllaries triangular to narrowly lanceolate, 1-3 mm wide. Corolla 1-2 cm. Achene obcolumnar, 2.5-4 mm, distinctly compressed, between lateral ribs with 3(-5) slender ribs on either side, space between slender ribs much wider than ribs, distinctly rugose when fully mature. Pappus 6-8 mm, ± persistent. Fl. and fr. May-Dec. 2n = 32.

Sonchus oleraceus is naturalized in all countries neighboring China and is anthropogenically distributed almost worldwide.

The entire plants are used medicinally.

Mountain slopes, forests, forest margins, fields, near water, open land, ruderal areas; 170-3200 m. Naturalized in Anhui, Fujian, Gansu, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, and Zhejiang [presumably originating from Europe and Mediterranean region].