Description from Flora of China
Herbs annual, erect, 20-60 cm tall. Stem stout, branched; branches slightly quadrangular, gray strigose, slightly inflated at nodes. Petiole 1-1.5 cm, long gray hairy; leaf blade oblong or oblong-obovate, 3.5-13 × 1.5-5 cm, papery, long white hairy and ciliate, narrowing toward base, margin undulate, apex acute or obtuse. Heads terminal, 1-3, usually purple, sometimes light purple or white, 2-2.5 cm in diam. Bracts 2, opposite, green, ovate or cordate, 1-1.5 cm, gray hairy; bracts white, purple at apex, ovate, 3-5 mm; bracteoles purple, triangular-lanceolate, much longer than bracts, 1-1.2 cm. Tepals not rigid after anthesis, lanceolate, 5-6 mm, outside densely white lanose, apex acuminate. Filaments connate into a tube, 5-parted at apex. Styles linear, shorter than tube of stamens; stigmas 2, furcate. Utricles subglobose, 2-2.5 mm in diam. Seeds brown, shiny, reniform. Fl. and fr. Jun-Sep.
Widely cultivated. Fujian, Guangxi, Guizhou, Hebei, Hubei, Shanxi, Sichuan, Xinjiang, Zhejiang [native to neotropics; cultivated and naturalized throughout tropical Asia].