An ancient shellbark hickory stands guard at Cincinnati's Spring Grove Cemetery and Arboretum.
The shellbark hickory is a large tree with shaggy gray bark and big compound leaves borne in a cylindrical crown. This uncommon hickory has a narrow, oblong crown and a relatively slender, straight trunk, usually free of branches for more than half its length. Shellbark can reach a height of 120 ft (36.6 m) with a trunk diameter of 3 ft (0.9 m). Twigs are stout and distinctly orange-brown in color. The bark is broken up into long thick plates which curl outward only slightly at their ends. The deciduous leaves are compound, 15-22 in (38-60 cm) long, with 5-9 (usually 7) leaflets. The terminal leaflet is the largest, 5-9 in (12.7-22.9 cm) long and 3-5 in (7.6-12.7 cm) wide. The fruit is between 2 and 3 in (5-7.6 cm) long, and the orange-brown husk splits open into four sections when ripe. The nut within is flattened, with prominent ridges and a sharp point at the end. Inside the nut's hard thick shell is an edible sweet, oily kernel.
Shellbark hickory is similar to - shagbark hickory (C. ovata), but shagbark usually has just 5 leaflets per leaf and bark plates that curl prominently outward.
This hickory's "shellbark" grows in thick plates that curl up at the ends - note the large plate curling up (and eventually off...) just beneath the branch (at right).
Shellbark hickory grows naturally only in the US from western New York through southern Michigan, Illinois, Missouri and Kansas, and south to Arkansas, Tennessee, Alabama and Georgia. There are a handful of isolated outlying populations in Louisiana, southern Georgia, southern Alabama, and North Carolina. Shellbark hickory occurs most abundantly in the Ohio and upper Mississippi valleys. This is a tree of the bottomlands and floodplains, often growing where it gets flooded during high water. It sometimes occurs in pure groves, but more often is mixed with other bottomland trees such as
red maple, sweetgum and chestnut oak.
Culture Light: Full sun. Moisture: Shellbark hickory tolerates shallow flooding for brief periods in spring. Otherwise it does best on rich, fertile soils with the ability to retain some moisture. Hardiness: USDA Zones 5 - 8. Propagation: Nuts should be planted as soon as they ripen, preferably where the tree is to be grown. Stored nuts require a pregermination chilling period.
The shellbark hickory features fine foliage and boasts big edible nuts beloved both by beasts and hungry humans.
Shellbark hickory nuts are the largest of all the hickories. They are relished by wildlife, especially bears, squirrels and foxes. People also eat the nuts which can sometimes be found in local markets. The dark brown wood is strong, hard and rigid. It is used for tool handles, especially axes and hammers. It was once one of the most important hickories for its wood, but large areas within its range have been overharvested.
Shellbark hickory is an uncommon tree in the wild and in cultivation. It would be suitable for a park, campus or estate.