5. Sonchus oleraceus Linnaeus, Sp. Pl. 2: 794. 1753.
苦苣菜 ku ju cai
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.
Mountain slopes, forests, forest margins, fields, near water, open land, ruderal areas; 1700-3200 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].
Sonchus oleraceus is naturalized in all countries neighboring China and is anthropogenically distributed almost worldwide.
The entire plants are used medicinally.