The hickory, genus Carya, contains about 15 species of deciduous hardwood trees belonging to the walnut family, Juglandcaeae. Eleven species are native to the eastern United States, and five of these are also found in adjacent regions of Canada. The offer four species occur in the southern United States, and two of these are also native to Mexico. Eight species are considered important in forestry in the United States.
Hickories have gray bark. The trunks are smooth when young but later become rough, furrowed, and in some cases shaggy. Small, greenish female flowers and male flowers in slender catkins are borne in spring with the leaves. The fruit, or nut, matures and falls in autumn. It has a hard shell and an oily, edible seed that may be bitter-tasting.
The pecan, C. Illinoensis, is large tree of the Missisippi Valley region. It produces edible nuts; its wood is used in furniture, flooring, boxes, and crates, and as a fuel for smoking meats. The bittternut hickory, C. cordiformis, is a medium sized-tree of the eastern United States. Its wood is used for the same purposes as pecan wood. The shell bark hickory C. laciniosa, is a large tree of the Ohio and Mississippi valley regions; it produces the hickory nuts used in commerce. Shagbark hickory, C. ovata, is large tree of the eastern United States and Canada used for lumber.