Perennial, erect herbs or undershrubs, usually covered with shining, scattered, stellate hairs, branches often red-tinged; leaves often rhomboid to ovate, crenate towards distal end, entire towards base, stipules linear, setaceous, longer than petioles; flowers axillary, solitary or 2-5 together; pedicels 2 times longer than petiole, jointed above the middle; epicalyx absent; calyx campanulate, angular, 5 prominent nerves, lobes splitting above, deltoid tips acuminate; petals yellow, rarely white, oblique, obovate, glabrous; stamens numerous, staminal column shorter than petals, anthers monothecous; carpels 10, awned, as long as the calyx, smooth or reticulate, styles as many as carpels; ovary minutely stellate-hairy; fruits schizocarps, mericarps usually 10, flattened trigonous, usually muticous with very short awns; seeds ovoid, smooth, black, obtusely trigonous.