三裂叶豚草 san lie ye tun cao

Annuals, 30-150 cm. Stems erect. Leaves mostly opposite; petiole 10-30(-70) mm; blade orbicular-deltate to ovate or elliptic, 4-15(-25) × 3-7(-20) cm, usually some palmately 3(-5)-lobed, both surfaces scaberulose and gland-dotted, base truncate to cuneate, sometimes decurrent onto petiole, margin usually toothed, rarely entire. Female capitula clustered, proximal to male; floret 1. Male capitula: peduncles 1-3 mm; involucres saucer-shaped, 2-4 mm in diam., scaberulose; florets 3-25. Bur pyramidal, 3-5(-7) mm, glabrous or glabrate, spines 4 or 5, apical, acerose, 0.5-1 mm, tips straight. Fl. Jul-Aug, fr. Sep-Nov. 2n = 24, 48.

Weed of disturbed sites, wastelands, damp soils; below 1600 m. Hebei, Heilongjiang, Hunan, Jiangxi, Jilin, Liaoning, Shandong, Sichuan, Zhejiang [native to North America].