Carya cordiformis

Native

Common

Moist to dry. Wet bottomlands, dry uplands. Moderately shade tolerant.

Early May to early mid-June

Green

40′ to 80′

This is a slow-growing, deciduous, hardwood tree. It rises on a single stem from a deep root system with a central taproot. In Minnesota mature trees are usually 40′ to 60′ tall and 12 ″ to 24″ in diameter at breast height. Large individuals can reach over 90′ in height and 48 ″ in diameter. It is a long-lived tree, often surviving 200 years.

The trunk is straight and slender. It is distinct into the upper part of the crown and is often free of branches for much of its length. The crown is narrow, rounded, and short. The branches are slender and ascending.

The bark on young trees is thin, smooth, and light gray, with grayish-yellow, irregular, vertical lines. It remains like that for many years. As it ages it separates into flat interlacing ridges and narrow, shallow furrows. In appearance it is much like the bark of green ash, with a diamond-shaped pattern. It does not develop loose scales.

The twigs are moderately stout, greenish-brown to gray brown, with numerous lighter dots (lenticels). They have whitish hairs near the tip but are otherwise hairless. They are round in cross section and have brownish-white, star-shaped pith. The leaf scars are slightly raised and 3-lobed to oval. They have many bundle scars that are either scattered or arranged in 3 clusters forming a monkey face pattern.

Terminal buds are sulphur yellow, ⅓″ to ¾″ long, slender, and flattened, with 2 to 4 valve-like bud scales. The scales are themselves densely scaly with yellow, bran-like scales, and have straight, soft hairs near the tip. Lateral buds are similar but shorter, diverge from the twig, and have 2 protective bracts at the base. The buds open valve-like when the new shoot emerges.

The leaves are deciduous, alternate, 6″ to 10″ long, and pinnately divided into usually 7 or 9, sometimes 11, rarely 5, leaflets. They are on 1¼″ to 2¾″ long, minutely hairy leaf stalks.

The upper 3 leaflets are elliptical to inversely egg-shaped, 2¾″ to 6″ long, ¾″ to 2⅜″ wide. The terminal leaflet is usually no larger than the adjacent pair. The remaining leaflets are similar in shape but progressively smaller. All leaflets are stalkless or nearly stalkless, including the terminal leaflet. The blades are widest in the middle and taper toward both ends. They taper unevenly to a blunt or acute base, and taper to a point at the tip with concave sides along the tip. The upper surface is dark green and sometimes hairy along the midvein but otherwise hairless. The lower surface is pale green, hairy along the midvein, and otherwise sparsely hairy, becoming hairless with age. The margins are finely or coarsely toothed with sharp, forward pointing teeth. They do not have hairs on each tooth. In autumn the leaves turn golden yellow.

Male and female flowers are borne on the same branch. They appear when the leaves are nearly full size in early mid-May to mid-June. The male inflorescence is 3 cylindrical, drooping clusters (catkins) of numerous tiny flowers. Each catkin is 1½″ to 4″ long. The 3 catkins are attached to a single stalk rising from the base of current-year twigs, and from leaf axils of previous season leaves. The female inflorescence is 2 to 4 flowers on a 5 ⁄16″ long spike at the end of current-year twigs.

The fruit is a nut enclosed in a thin, leathery husk. The husk is ¾″ to 1¼″ long, slightly wider, 1 ⁄16″ to ⅛″ thick, and globular. It is not compressed or is only slightly compressed on the top. There are 4 wings extending from a short, sharp tip to below the middle. The fruit ripens in September and October and is dispersed from September to December. The ripened husk splits open at the base to release the nut. The nut is light brown and elliptic to egg-shaped. It is not compressed or is only slightly compressed on the top, and is rounded at the base. The shell is thin and the kernel is bitter.

Northern shagbark hickory (Carya ovata) bark forms peeling strips. Current-year twigs are hairy. The buds are tan to dark brown and have 6 to 9 thin, overlapping scales. The leaves have 5, rarely 7, leaflets. The leaf margins have small tufts of hairs. The fruits are larger, 1⅜″ to 19 ⁄16″ long, and have a thick, woody husk.

Green ash (Fraxinus pennsylvanica) buds are reddish-brown, not yellow.

The champion bitternut hickory in Minnesota is on private property in Canton, in Fillmore County. In 2002 it was measured at 94′ tall and 73″ in circumference (23¼″ in diameter).