Identifying trees using features other than leaves
Michigan State University Extension recommends late summer as a great time of year to hone your tree identification skills because the leaves are still on the trees – but won’t be for long!
There are many features that may be used to identify a tree, and if you have an interest in trees, it can be fun to learn about the variety of unique characteristics of each species. Learning the characteristics other than leaves can be difficult, that’s why Michigan State University Extension educators think it is a good idea to begin to learn with the leaves on the trees, and then continue the challenge once that easily recognizable clue has fallen off.
Leaves are a great starting point for tree identification. And as mentioned above, leaves can provide a confirmation of species identification as you begin to test the use of other characteristics. A couple of tips about using leaves for identification may help to make things easier. The leaves found on the lower branches of deciduous trees, or trees that lose their leaves, may be larger than the leaves found on the upper branches and are typically called, “shade leaves” because they spend most of the summer in part to full shade. Leaf shape, and not size should be used in identification.
Tall trees with leaves well out of reach can provide some challenges to confirming a tree species. In this case, use binoculars to get a close up view of the leaves. Or search the ground around the tree for leaves that may have fallen off the tree. You may also find other signs that can confirm the species of the tree in question in the form of seeds or clippings of entire branches delivered by squirrels for your use in identification.
Opposite versus alternate branching
Most tree identification resources start with asking if the tree has opposite or alternate branching. This refers to the orientation of the twigs with the branches. Opposite branching refers to a branching pattern where side branches, leaves and leaf scars grow from the stem directly across from each other. Examples of trees that grow with this pattern include maples, ash and buckeye trees. Alternate branching refers to a pattern where side branches, leaves and leaf scars do not grow directly across from each other. Alternate branching is much more common than opposite. So, when you spot an opposite branching tree, you’ve greatly narrowed down the possible species of the tree you are identifying.
Identifying a tree by its bark requires practice. Bark characteristics can change drastically as the tree ages. Bark differs from species to species by color, texture, and pattern. The bark for some species may be more distinct than others, so start with taking serious note of the bark on the trees that are in your immediate surroundings. Use the leaves to confirm the species. Then try to spot this tree species by bark in other places close by. Once you’ve mastered one species of tree, move on to the next, paying special attention to differences with the first. Continue this pattern and you’ll be a master of tree identification using bark just about the time the leaves fall off the trees.
Amazingly enough, each species of tree also has a unique twig. Twig refers to the outermost portion of a branch that grows new leaves or needles. Twigs have a variety of characteristics that may be used for identification of the tree from which it came including the color, texture of bark, thickness, and shape. The most commonly used characteristics, however, are the bud that forms at or near the tip of the twig and the scar left on the twig from current and sometimes pervious years leaves.
Each spring, trees grow new leaves or needles so that they most efficiently produce food throughout the summer that supports reproduction and helps sustain the tree through the year. The new leaves grow, or elongate out of buds that the tree created near the end of the previous growing season. More information about buds can be found in a previous Michigan State University News article about trees preparing for winter. Buds have different shapes, colors, sizes, and features making buds one of the easiest ways to identify a tree. For example, maples generally have pointed buds, while oaks always have a cluster of buds at the end of each twig.
Leaf scars refer to the outline of the petiole, or stem of the leaf, that is left on the twig from previous year’s leaves. The same shapes may also be visible when the current year’s leaves are carefully pulled off the twig. Within the leaf scar is usually evidence of the water and nutrient transport tubes that connected the petiole to the tree’s vascular system.
As you may now realize, there are a number of characteristics that may be used to identify a tree. This article provided a few of the easiest ways to start the journey. Once you begin to notice a tree’s unique characteristics, it’s hard to resist.
Michigan Tree Identification Resources: