Description from Flora of China
Herbs annual, biennial, or perennial, often hispid or tomentose, hairs often mostly simple. Leaves entire or palmately lobed. Flowers solitary, axillary, yellow or red. Epicalyx lobes 5-15, filiform, very rarely lanceolate, persistent. Calyx spathaceous, splitting along 1 side at anthesis, apex 5-toothed, caducous with corolla. Corolla with a dark red center, funnel-shaped; petals 5. Staminal column shorter than corolla, 5-toothed at apex, with anthers at base. Ovary 5-loculed; ovule many per locule; style single with 5 sessile capitate stigmas. Capsule elongate, loculicidal, pubescent or hispid. Seeds reniform or globose, many, glabrous, smooth.
About 15 species: tropical and subtropical regions in E Hemisphere; six species (one endemic, one introduced) in China.