Hickory Tree Identification

Hickory trees are commonly found in North America and certain parts of Asia. These trees belong to the genus Carya in the family Juglandaceae. There are around 17 to 19 species of these trees, from which around 11 to 12 species are found in the United States. Some of the commonly found species in North America are pignut hickory (Carya glabra), shagbark hickory (Carya ovata), shellbark hickory (Carya laciniosa), pecans (Carya sect. Apocarya) and bitternut hickory (Carya cordiformis). While these species may look somewhat similar, they have different features and so, hickory tree identification may be difficult.

How to Identify Hickory Trees

In general, these trees can be described as deciduous trees with pinnately compound leaves. Their flowers are yellowish-green in color and are found to develop as drooping catkins of three groups. They produce large nuts, which are edible in some species like pecans. These nuts are round with four winged husks. Hickory tree nuts have a length of one to two inches, with a dusty yellow color. While mockernut has reddish-brown husks, those of pignut hickory have no ribs. Shellbark hickory produces the largest nuts, among the different hickory species and they are also sweet and edible. The following are some of the general observations that may help you in identifying hickory trees.

Height of the Tree

Even though, it is difficult to identify different hickory species on the basis of tree height, there are certain factors that may help you in this task. The shortest among the hickory species is shellbark, with a height of around 30 to 60 feet and a trunk diameter of one foot to three feet. You may find bitternut, mockernut and pignut hickory trees with similar trunk diameter, but a height of around 50 to 70 feet. Shagbark hickory may grow to a height of 60 to 80 feet, but, some of them are found to have a height of more than 100 feet.

Shape of Leaves

Another common feature that will help you in hickory tree identification is the pinnately compound leaves with several leaflets. Almost all species, except pignut and shagbark hickories have seven to 11 leaflets. The latter are found to have five to seven leaflets. In case of pecans, the number of leaflets can be around seventeen. So, hickory leaves are always found to have an odd number of leaves. Finely toothed leaflets are found in bitternut, mockernut, pignut and shagbark hickories. Mockernut hickory leaves has a dense hairy underside with an orangish brown color. These leaves are also aromatic. Even bitternut hickory leaves have slightly downy underside. Even though, the leaf color is found to be green in different hickory species, you may find it in different shades. Shagbark hickory has a yellowish-green leaf color, whereas, nutmeg hickory leaf has a whitish underside with dark green upper surface. Most of the hickory trees are found to change foliage color to yellow during fall. Another point of distinction between the different species is the shape of the crown, which is rounded in mockernut and cone-shaped (rounded in some cases) in bitternut. Pignut hickory is found to have droopy or spreading branches.

Color and Texture of Bark

Bitternut hickory bark is thin, tight and hard with a gray color, that changes to silvery shades as the tree ages. Even the bark of this tree develops shallow furrows and ridges with age. In young pignut hickory trees, the bark is found to be smooth with a light gray color. As they age, the color changes to dark gray and the tree develops scaly ridges. One of the prominent factors in shagbark hickory tree identification is the light gray bark that is found to peel as thick vertical plates (with a length of more than a foot) with both ends curling outwards. Similarly, shellbark hickory tree can be identified with its peeling bark that comes out in smaller strips (as compared to shagbark variety).

In short, hickory tree identification can be a little tricky, as you may come across different species. The above said is only a brief overview about their features that may help you in identifying these trees. However, a detailed study about individual species will be always beneficial in distinguishing them.