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.