Garden Variety: What to look for when identifying leafless trees
Have you ever noticed a tree and wondered what kind it was?
Perhaps it was in your yard, a neighbor’s yard or something you noticed on a walk in the woods. Whatever the case, trees are usually most easily identified by their leaves. In the winter, deciduous trees are more of a challenge because they have shed their leaves, but identification is still possible. During this dormant season, bark, buds, fruit and other distinguishing characteristics offer the biggest clues for tree identification.
Which factor to start with depends on the type of tree. A few species have standout characteristics. For example, shagbark hickory has bark that appears to peel from the trunk in large clumpy sheets as the name implies. An oak tree might have acorns still hanging in it or piled on the ground beneath.
Look for something that might set easily set the tree apart.
If the tree has a standout feature, work to identify it based on that.
Other trees with characteristic bark are hackberry, with a warty or corky appearance; birch, with papery peeling bark; and sycamore, with green and white patchy bark.
There are a few outliers such as paperbark maple, which has bark that more closely resembles birch than the bark of other maples.
Honey locusts, black locusts, Kentucky coffeetrees and catalpas may have seed pods still hanging in the tree. Oaks, hickories, walnuts and pecans may have nuts on the ground below the tree.
Honey locust and black locust may also be identified by their thorns or spurs unless they are thornless varieties. Hawthorns, Osage oranges and some pear trees may also have thorns or spurs.
If the bark seems nondescript and the tree lacks fruit, nuts, seed pods and thorns, look more closely at the buds. Bud arrangement is the next clue for identification.
There are three types of bud arrangements: opposite, alternate and whorled. Opposite means that buds are right across from each other on the twigs. Alternate means that they alternate along the twig. Whorled means that three or more buds emerge from the same point along the twig.
Whorled bud/leaf arrangement is the least common for trees. It is much more common in shrubs and herbaceous plant species. The only species common in this area with whorled leaf arrangement is catalpa.
Catalpa may also be identified in winter by its long, bean-like seed pods and the overall shape of the tree, if mature.
Opposite bud/leaf arrangement is less common than alternate arrangement. The kinds of trees with opposite bud arrangement commonly found in the Midwest are maples, ashes, dogwoods and horse chestnuts.
Sometimes the Caprifoliaceae family (honeysuckles and viburnums) and buckeyes are included in references. Honeysuckles and viburnums are typically large shrubs which are sometimes confused with small trees. Buckeyes are closely related to horse chestnuts and sometimes grouped with them.
In some tree identification guides, experts recommend looking at leaf scars instead of buds. Leaf scars are the marks on the twigs where leaves have fallen off. The only difference here is in looking at where leaves have been in the previous season versus where leaves will be in the coming spring.
Identify which bud/ leaf arrangement category the tree falls into, then use additional clues such as the shape and size of the tree or the growing location to further narrow down the possibilities.
At this point, a tree identification key specific to winter or dormant features is essential. There are several options online and many books and pamphlets on the subject. Identification efforts are most likely to be successful when using a key from Kansas or a neighboring state or something that implies it is specific to the Midwest.
If using online resources, seek out options that are provided by universities, government organizations such as the U.S. Forest Service, or other organizations interested in trees and forestry.
— Jennifer Smith works in regulatory horticulture and has worked as a horticulturist for various government entities. She has experience in landscape design and maintenance and as an educator.