Herbs; leaves opposite, with or without stipules, blades entire; flowers hypogynous, usually bisporangiate, solitary or in cymose clusters; sepals usually 5 (4), separate or united; corolla regular, of 5 separate petals, or lacking; stamens separate. usually as many as or twice as many as petals or sepals, but sometimes not exactly; carpels 2-5, united; styles and stigmas as many, or rarely united; ovary l -Ioculed, placenta free central or basal, or 3-5-loculed below, the partitions more or less completely formed; fruit a utricle (I-seeded) or a capsule dehiscent by as many or twice as many valves or teeth as styles.