Annual or perennial herbs or dwarf-shrubs. Leaves opposite, entire, exstipulate. Flowers hermaphrodite, rarely unisexual, in cymose inflorescences or solitary. Calyx gamose¬palous, usually tubular, mostly 10- but sometimes also 20-, 30- or 60-nerved; teeth 5. Petals 5, rarely 0, white, red, pink, purple or green, rarely yellow, long-clawed; limb entire to lobed, usually 2-fid; coronal scales usually present between limb and claw, sometimes rudimentary or 0. Stamens 10, unequal. Ovary mostly 3(-5)-celled at base, 1-celled in upper part, many-ovuled; styles usually 3, alternating with sepals. Capsule often borne on a carpophore, rarely sessile, oblong to spherical, dehiscing by 6 (-10) teeth. Seeds more or less reniform.