Identify Common Hickory - Major Hickory Species in North America

Hickory Trees in the Walnut Family - Juglandaceae

carya ovata (shagbark hickory)
Nuts of shagbark hickory. (David Q. Cavagnaro/Photolibrary/Getty Images)

Trees in the genus Carya (from Ancient Greek for "nut") are commonly known as hickory. The worldwide hickory genus includes 17–19 species of deciduous trees with pinnately compound leaves and large nuts. North America has the overwhelming edge on the number of native hickory species.

A dozen or so species are native to North America (11–12 in the United States, 1 in Mexico), where there are between 5–6 species from China and Indochina. The hickory tree, along with the oaks, dominates the hardwood forests of eastern North America.

The Common North American Hickory Species

Identifying the Common Hickories

There are six species of Carya that make up the most common hickories found in North America. They come from three major groups called shagbark (which has shaggy bark), pignut (which rarely has shaggy bark) and the Pecan group. Shaggy bark is a great identifier to separate the shagbark group from the pignut group.

Hickories have a nutritious nut meat that is covered by a very hard shell covered by a splitting husk shell (as opposed to a larger walnut that drops with a complete husk cover). This fruit is located at the twig tips in clusters of 3 to 5.These should be searched for under a tree being identified. They have branching flowering catins just below the emerging new leaf umbrella-like dome in spring.

The leaves of hickory are mostly alternately placed along the twig in contrast to a similar looking ash tree leaf that is in an opposite arrangement. The hickory leaf is always pinnately compound and the individual leaflets can be finely serrated or toothed.

Dormant Identification

Hickory twigs have tan 5-sided or angled soft centers called piths which are a major identifier. The tree's bark is variable along species lines and not helpful except for loose, flaky bark on the shagbark hickory group. The tree's fruit is a nut and splitting husks are often visible under a dormant tree. Most hickory species have stout twigs with large terminal buds.