Shrubs to small trees, with stellate hairs. Leaves opposite, simple, margins entire or crenate. Inflorescence terminal or axillary, cymose. Flowers bisexual, 4-merous; sepals fused into an unlobed or 4-(8-)lobed cup; petals valvate, fused for most of their length or sometimes separating (C. alba, C. aemula), persistent or deciduous; stamens 8, free, erect; disc 8-lobed; carpels 4, 1-locular, lacking sterile apex, style arising from c. middle of the carpels, ovules 2 per loculus. Follicles not transversely ridged; seeds dull brown, released explosively with elastic endocarp.
11 species, largely restricted to the eastern States and South Australia (C. reflexa extends slightly into Western Australia).
Hybrids occur frequently between sympatric species. Many species and cultivars are grown for ornament and site rehabilitation.