Annual herbs, usually somewhat succulent. Lvs alternate, pinnatifid; stipules 0. Fls solitary on long peduncles, axillary, actinomorphic, ☿. Calyx 3-5-merous; sepals valvate or slightly imbricate, free. Petals 3-5, free, contorted, slightly perigynous. Stamens 6-10; filaments free, sometimes glandular at base; anthers 2-locular, dehiscing longitudinally. Ovary 3-5-locular, fused to a common gynobasic style with 3-5 short lobes; ovules solitary in each carpel, orthotropous. Fr. separating at maturity into 3-5 nutlets, each representing a free indehiscent carpel; seeds lacking endosperm.