Walnut trees are any species of tree in the plant genus Juglans, the type genus of the family Juglandaceae, the seeds of which are referred to as walnuts. All species are deciduous trees, tall, with pinnate leaves , with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts (Pterocarya), but not the hickories (Carya) in the same family.