Dear Aggie

Dear Aggie, how can I identify trees in the winter?

When walking by trees in the winter, you may notice that it’s harder to identify some of the species. While leaf type can be used to identify deciduous trees from spring to fall, the leaves may fall before the winter begins, making identification in winter difficult. Since evergreen species (like pines and spruces) can be identified by their needle-like leaves, how do you identify deciduous trees without their leaves?

The arrangement of the twigs, which develops from each bud, can be used for identification. Trees typically have alternate or opposite arrangements, but they can have whorled arrangements or other types. If alternate, the buds are single at each node and are borne along the stem in an ascending spiral. Some examples of alternates are oak, cottonwood, and walnut. If opposite, the buds of the node are paired and are opposite to each other. Some opposite examples include maple and ash. Whorled arrangements have more than 2 buds at each node. Arrangements can be tricky though, as different species may have different types of arrangements, like the catalpa trees which have whorled or opposite arrangements.

Another identifier is the size of the twigs. Some trees may have stout or slender sized sprigs. For example, the black-locust can have stout twigs versus the honey-locust having slender.

The pith is the soft, central cylinder tissue inside twigs and can be solid, chambered, or diaphragmed. The most common pith is solid. The chambered pith is hollow with separations that create small, empty cavities. Some examples are butternut and black walnut. The diaphragmed pith is solid with separations that create small, filled cavities. Some piths will even release an aroma like a cherry tree, and they may be light-colored or dark-colored.

The bark is an easy indicator as well. There is smooth, ridge and furrowed, and plated types. Sometimes, the younger bark may be different from the mature bark. You can observe the differences between the younger version and mature version of the specific plant species.

Buds can be identified by true terminal or false terminal buds. When you look at basswood, they would have false terminal buds versus sassafras that have true terminal buds.

Trees also tend to have different levels of hairiness on the buds and twigs. For example, box elder has hairy buds versus black cherry that has glabrous buds.

You can identify the scales on the buds by their colors and the number of scales. Some colors may vary from red (like a red maple) to brown/pale gray (like a cranberry cotoneaster). The buds can also have 1, 2, or many scales.

There are other parts like thorns, prickles, spines, and scars that can help you identify different tree types.

Even though the leaves have fallen in the winter, there are many other parts that you can use to identify deciduous trees. If you are interested in identifying a specific tree, you can view winter keys and other guides that can help identify the deciduous trees.

If you have questions about tree identification, feel free to contact our local CCE Office at 315-788-8450 or Cierra Williams at clw247@cornell.edu.

Last updated January 22, 2025