Herbs or shrublets. Stipules 0. Leaves opposite. Sepals united to form a tubular or dilated calyx which is 5-toothed with 10 principal veins. Flowers unisexual or bisexual. Petals 5, with a long narrow claw and a dilated, 2-fid or simple lamina, often with scales at the base of the lamina. Stamens 10. Styles 3 (in ours). Capsule many-seeded, opening from the apex by 3 or 6 teeth or valves. Seeds numerous.