Plant identification is one of the most common questions received by the Horticulture Answer Service at the Missouri Botanical Garden. And it’s an important one, too. Before you know how to care for a plant, you need to know what it is. The same is as true for trees as it is for tomatoes and tulips. So how do you figure out what type of tree is blooming beautifully in spring, throwing shade in summer, or exploding with fall color?
Flowers, Foliage, Fruit, and Bark
There are a number of characteristics that can help you identify trees—including bark, habitat, form, structure, and even smell or taste. But four of the easiest things to spot are flowers, foliage, fruit, and bark. Although there are many exceptions (and being an exception can itself be an identifying feature) these traits are helpful identifiers in certain seasons.
Spring is one of the best times to identify showy flowering trees, as distinct blooms make them easy to spot in the landscape. Take note of the size, shape, smell, petal color, and even the timing of the bloom.
Trees to look for: Redbud (Cercis canadensis), Magnolia (Magnolia spp.), Tulip poplar (Liriodendron tulipifera), Pawpaw (Asimina triloba)
Term to know: Catkins are clusters of small, generally inconspicuous flowers that form on several types of trees in spring. This notable flower structure can be found on oak, birch, willow, and hickory trees among others.
Summer and fall are the best times of year to take a close look at the foliage, and use it to help identify trees. Leaf shape and size are important, but so are other indicators such as color and texture. Other clues to look for include alternate or opposite arrangement, leaf margin and simple versus compound leaves. The transition to fall allows you to further examine the foliage, as autumn color can be another clue for identification.
Trees to look for: Sweetgum (Liquidambar styraciflua), White ash (Fraxinus americana), Ohio buckeye (Aesculus glabra), Sugar maple (Acer saccharum)
Term to know: Understanding the difference between simple and compound leaves can be a big key to unlocking tree identification. Simple leaves have a single, undivided blade of foliage that attaches to the petiole (a petiole is a stalk that supports the leaf and attaches to the stem). Sweetgum and maple trees have simple leaves. Compound leaves are divided into multiple leaflets attached to the central stalk. Ash and buckeye are examples of compound leaves.
Fall is also a great time to examine the fruits of many trees. The fruits often form in the summer and ripen in the fall, and become more visible as trees drop their leaves. As with flowers and foliage, noting the color, size, and shape will help you better identify the fruit and the tree it came from. An added incentive to learn tree fruits—some are edible and delicious!
Trees to look for: Bur oak (Quercus macrocarpa), Osage Orange (Maclura pomifera), Black Walnut (Juglans nigra), American persimmon (Diospyros virginiana)
Term to know: Cupules are a cup-like structure that surrounds or partially surrounds the fruits of many trees in the Fagaceae family. In oaks, it’s the “cap” of an acorn. In chestnuts, the cupule completely surrounds the fruits and is covered in sharp spines to deter foraging animals.
Winter can be one of the most challenging seasons to identify trees, since the deciduous species won’t have flowers, fruits, or leaves. Evergreens such as American holly (Ilex opaca) and Eastern red cedar (Juniperus virginiana) tend to stand out. Winter is a great time to hone your identification skills by focusing on bark.
Trees to look for: American sycamore (Platanus occidentalis), River birch (Betula nigra), Common hackberry (Celtis occidentalis), Shagbark hickory (Carya ovata)
Terms to know: Exfoliation is a process by which some trees shed their outer bark. Sycamores have famously mottled trunks revealing a greenish-white bark underneath as they shed layers. This characteristic is also found in the peeling, papery bark of river birch and the shaggy look of shagbark hickory.
If you can identify a tree using one of these four features, visit it again in a different season and take note of other distinguishing traits. The best way to become better at identifying trees is to spend time with them and pay attention. The more time you spend, the more you’ll notice. The more you notice, the more patterns will become clear. And those patterns are ultimately what will help you identify, understand, and appreciate trees in ways you may not have before.
“The best way to become better at identifying trees is to spend time with them and pay attention.”Tweet
A Walk in the Park
Once you know what to look for, tree identification becomes as easy as a walk in the park. The easiest place to start your tree identification journey is at the Missouri Botanical Garden. Many of the Garden’s 5,000-plus trees are labeled with the common name, species name, and other information, making them readily identifiable.
The Garden also offers classes on tree identification, tree photography, and gardening with native trees. Visiting the Garden can help you familiarize yourself with the different tree families and specific species.
After you’ve built a nice knowledge base at the Garden, head next door to Tower Grove Park. The park is a national historic landmark with more than a few ties to the Garden and its founder Henry Shaw. It’s also a Level II Arboretum—home to about 7,000 trees, including two state champions. Combined with the Garden’s collection, the two sites offer an urban canopy of more than 12,000 trees on 368 acres in the city of St. Louis.
The Park, like the Garden, has mapped its tree collection and made the information available publicly. Unlike the Garden there are no labels on the trees of Tower Grove Park—which for the sake of this exercise means you can’t accidentally peek at the identification before you’ve decided for yourself.
This extra layer of difficulty will help you better learn to identify trees in a more natural, but still curated, space. The Park’s tree map links to the Garden’s PlantFinder resource, allowing you to learn more about any tree you encounter on your next walk.
More from Tower Grove Park: Autumn Tree Walk Guide
There’s even help if you want to identify the tree right outside your own house. The Show MO Trees website has mapped tens of thousands of trees in public places, especially along streets. In addition to identifying the trees, the site also includes information about the eco-benefits of each tree, such as the amount of greenhouse gases sequestered.
When you think you’ve mastered basic tree ID, you can really put your new skills to the test at Shaw Nature Reserve. The Garden’s campus in Gray Summit offers 2,400 acres of Ozark borderland habitats. You’ll find plenty of oak, hickory, and maple species in the woodlands, along with redbuds, dogwoods, and a few surprises mixed in. Most of the trees here aren’t labeled or mapped, so you’ll be relying solely on your newfound knowledge to make a proper tree ID.
This particular guide to tree ID focused mainly on Missouri-native trees, or those found commonly in cultivation throughout the St. Louis region. It only begins to scratch the surface of tree species diversity found throughout the world.
As you become more familiar with the trees around you, do what they do and branch out. Try to learn more about trees in other countries and climates, especially in places you might visit. Consider keeping a list of all the trees you ID and see how long it can get. Plant identification is a skill that builds upon itself the more you use it. In the case of tree ID, you just have to remember to look up!
Cassidy Moody — Senior Digital Media Specialist