Pubescent annual or perennial shrubs, often with glandular as well as stellate hairs. Leaves petiolate, often cordate, rarely lobed, dentate or crenate, acute to acuminate. Inflorescence axillary, flowers solitary or racemose; epicalyx absent; pedicel articulated in upper half; calyx-lobes joined basally only or for most of length; corolla yellow or orange; styles equal in number to carpels; stigma capitate. Fruit with deeply depressed central region, eventually splitting into mericarps for dispersal or remaining attached at base; mericarps 5–17, twice height of columella, 1-celled, apically and dorsally dehiscent when remaining attached, acute or acuminate apically, sometimes awned, 1–3-seeded.
At least 100 species in tropical and warm-temperate parts of the world; 28 species in Australia, all but 4 native.