Twigs are much stouter and glabrous, or only slightly hairy, when young with orangish-brown bark. The bark of the trunk is shaggy with long thin strips separating from the trunk, as does the shagbark hickory. Leaves are composed of five to nine, usually seven, leaflets on a leaf stalk that is abruptly thickened at the base. The leaf base remains after the leaflets fall and often curls backward. Flowers are monoecious.
Male flowers are catkins and showy, while the female flowers are green and inconspicuous.
May. The fruit of this species is a nut enclosed in a thick, hard husk that splits into several pieces. The nuts are larger than shagbark hickory and are borne singly or in pairs. The kernel of the shellbark hickory is light brown, sweet, and in demand as a food. Shellbark hickory is second in popularity to pecan. The wood differs little from that of the shagbark hickory.