Description from Flora of China
Sabdariffa rubra Kosteletzky.
Herbs annual, erect, to 2 m tall; stems purplish, robust, glabrous. Stipules filiform, ca. 1 cm, sparsely villous; petiole 2-8 cm, sparsely villous; leaf blade dimorphic; blades on proximal part of stem ovate, those on distal part of stem palmately 3-lobed, lobes lanceolate, 2-8 × 0.5-1.5 cm, base rounded or broadly cuneate, margin serrate, apex obtuse or acuminate, glabrous; basal veins 3-5, glanduliferous along midrib on abaxial surface. Flowers solitary, axillary, subsessile. Epicalyx lobes 8-12, red, lanceolate, connate at base, 5-15 × 2-3 mm, sparsely long hirsute, with spiny appendix near apex. Calyx purplish, cup-shaped, connate for ca. 1/3 length, ca. 1 cm in diam., fleshy, sparsely spiny and coarsely hairy, lobes 5, triangular, 1-2 cm, acuminate. Corolla yellow with dark red center, 6-7 cm in diam. Capsule ovoid-globose, ca. 1.5 cm in diam., densely coarsely hairy. Seeds reniform, glabrous. Fl. summer-autumn.
The fleshy calyx and epicalyx are edible, both fresh as a vegetable and dried as a tea.
Cultivated. Fujian, Guangdong, Hainan, Taiwan, Yunnan [probably originating in Africa, now cultivated throughout the tropics].