Description from Flora of China
Herbs or subshrubs, rarely woody, stellate puberulent. Stipules lanceolate; leaves simple, margin serrate. Inflorescence terminal or axillary, cymose, often congested. Flowers small, bisexual. Calyx 5-lobed. Petals 5, spatulate, persistent. Stamens 5, connate at base, opposite to petals; anthers 2-thecate, thecae parallel. Ovary sessile, 1-celled; ovules 2; style clavate or fimbriate at apex. Capsule 2-valved. Seed 1, with copious endosperm; cotyledons flat.
About 50 species: mostly in tropical America; one species in China.