Perennial shrubs or herbs, sometimes annual, stellate-pubescent. Leaves alternate, petiolate; stipules deciduous. Flowers bisexual, in axillary or terminal racemes or corymbs; epicalyx of 3 narrow bracts, or absent; calyx 5-lobed, c. half the length of petals; petals 5, usually yellow, orange, rose or purple; styles equal in number to carpels; stigma capitate. Fruit ± spherical, stellate-pubescent; mericarps 5–20, the upper part dehiscent and smooth, the lower part indehiscent and wrinkled or reticulate, 1–3 seeded; seeds reniform, glabrous to pubescent.
About 50 species from America; 1 species naturalised in Victoria.