Tree Identification Basics
by Shane Gibson, Environmental Education Director
This article originally appeared in the fall 2020 issue of The Twig, our member newsletter. To see a PDF of the print version, more articles, and past issues, click here.
Tree identification can be made simple. That doesn’t mean you will determine the exact species 100% of the time, but you will be able to narrow down your choices to get you one step closer to a positive identification. Common characteristics used to identify trees are leaves or needles, bark, branching, fruit, flowers, and buds.
The first thing I always look for, whether leaves are on or have fallen off, is the branching: is it opposite or alternate? Opposite would be like your arms, directly across from each other. Alternate branching is like your right arm and left leg. Don’t stop at just one set of branches when looking for opposite and alternate. Sometimes a branch on an opposite-branched tree may be broken off, giving the appearance of alternate. But an alternate-branched tree will never appear opposite.
So why do I like to start with branching for tree ID? If your tree has opposite branching, you have narrowed down your choices to five trees. There is a saying to help you know which five trees in Indiana will have opposite branches: MAD Horse Buck. MAD is maple, ash, and dogwood. Horse is horse chestnut and Buck is buckeye. So if you are using the 101 Trees of Indiana field guide, you have eliminated 95% of your choices. Now you can observe other features such as bark or leaf structure (simple or compound?) to narrow your choices even more. This method became important for me to identify maple trees in winter for tapping to make maple syrup.
Another way for the novice to identify trees is to use a key and answer questions to deduce or draw a reasonable conclusion. In the book Fifty Trees of Indiana, a key is provided in the center. The Arbor Day Foundation has a very easy-to-use tree identification guide at arborday.org, which will walk you through a few steps to reach your conclusion.
I have made some simple teaching posters out of cardstock that have been durable and used often the past five years as Sycamore’s educator. These tips and methods can be utilized by people of any age and skill level. I have to admit, when doing a tree lesson a few years ago with Ms. Harding’s 2nd grade class at Marlin Elementary in Monroe County, the students taught me about pinnacle and palmate features of leaves. I now incorporate that aspect of ID into my lessons and as another detail in helping me identify trees.