Description from Flora of China
Herbs annual, to 1 m tall. Stem red-brown, slightly yellowish puberulent; branches slender. Petiole 0.9-1.6 cm, with yellowish, long, rigid hairs; leaf blade ovate or broadly ovate, 4.5-6.5 × 3-4 cm, sparsely pilose on both surfaces, glabrescent, basal veins 5-7, lateral veins 3-6 pairs, base rounded, margin serrate, basal pair of teeth usually elongating into filiform or caudate appendages, apex shortly acuminate or acute. Flowers solitary or several together in cymes, axillary or leaf-opposed; peduncle and pedicel very short or absent. Sepals 5, purple-red abaxially, narrowly oblong, ca. 5 mm, semi-foveolately boat-shaped distally, apex awned. Petals 5, yellow, nearly as long as sepals, obovate. Stamens many, yellow, ca. 3 mm. Ovary 3-5-loculed, long cylindrical, puberulent; style rodlike; stigma beaklike, 5-toothed. Capsule cylindrical, angled, 3-5-valved, 1.2-2.5 × ca. 0.5 cm, apex 3-5-angled, awns bifurcate. Seeds separated by transverse septum. Fl. summer-autumn.
Widely cultivated. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [Bangladesh, Bhutan, India, Indonesia, Malaysia, Myanmar, Nepal, Pakistan, Philippines, Sri Lanka, Thailand, Vietnam; tropical Africa, Australia, Central America, West Indies].