Small, annual herbs. Lower leaves more or less rosulate, the rest opposite, all exstipu-late. Cymes terminal, umbellate. Pedicels unequal, deflexed after flowering. Sepals 5, free, persistent. Petals 5, entire or denticulate. Stamens 3-5 or 8-10. Hypogynous disk present. Ovary 1-celled, many-ovuled; styles 3 (-4-5). Capsule oblong-cylindrical, opening by 6 revolute teeth. Seeds plano-convex or concavo-convex, longitudinally keeled, covered with rows of tubercles.