is a medium-sized plant family with 119 US species, in 14 genera. Plants may be trees, shrubs or herbs, with oppositely-attached leaves that usually have toothed margins, but are not compound. Leaves lack stipules. The inflorescence is a spherical, elongated or branched cluster of small, bilaterally symmetric flowers, each consisting of five (less often four) sepals fused into a calyx, and five (or four) petals that form a narrow, tubular corolla, opening to small, spreading lobes. The corolla lobes often have a deep notch at the tip. Flowers have four or five stamens and one style.