An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Hamamelidae of the class Magnoliopsida (dicotyledons). The order consists of two families: the Juglandaceae with a little over 50 species and the Rhoipteleaceae with only one species. Within its subclass the order is sharply set off by its compound leaves. Juglans (walnut and butternut) and Carya (hickory, including the pecan, C. illinoensis) are familiar genera of the Juglandaceae.