Annual or perennial herbs, rarely shrubs, glabrous or with simple, branched, or glandular hairs; stems erect or prostrate. Leaves petiolate, 2- or 3-times divided (in Australia), segments narrow-linear. Inflorescence a raceme. Sepals erect or ascending; petals yellow to creamy white, sometimes shorter than sepals; stamens 6. Fruit linear, oblong, or clavate and elongate (more than 3 times as long as broad), rarely elliptic (not elongate), terete, dehiscent; style absent or minute; valves with distinct midvein. Seeds in 1 row per locule, mucous.
About 45 species mainly from America and the Canary Islands; 1 species naturalised in Australia.