XV. NYCTAGINACEÆ.
Trees with alternate stalked persistent leaves without stipules. Flowers perfect or unisexual; calyx corolla-like, 5-lobed; stamens 5—8; ovule campylotropous. Fruit anthocarpus, crowned by the persistent teeth of the calyx. Seed erect; cotyledons unequal, folded round the soft scanty albumen; radicle short, inferior, turned toward the hilum. A family of about twenty genera widely distributed chiefly in the warmer and tropical parts of the New World, with a single arborescent representative in North America.