Identifying Local Trees in Winter

 

Recognizing and identifying trees can be a great pleasure.  Knowing trees well enough to understand how they fit into the local ecosystem, and how they can be used, allows us to look around at the trees in our community with even greater appreciation.  But there are so many trees!  How can you learn to identify them without carrying around a heavy field guide?

This was our quandary as my novice Tree Steward colleagues and I began a project to inventory the shrubs and trees within the Williamsburg Botanical Garden in the winter of 2020.  We stood there looking around at hundreds of trees, most of them bare, wondering what we had gotten ourselves into.

 

 

We had all spent a morning with Dr. Stewart Ware, Professor Emeritus of Biology and Ecology at William and Mary, learning how to identify bare branches and buds using his “A Winter Twig Key to Common Leafless Dicot Trees in the Williamsburg Area”  And, we had walked with him through the winter woods observing trees, and we were all learning about various trees in our classes.  Finally, our team met at the garden armed with field guides and magnifiers, ready to apply our new skills.

But Where to Begin?

Sometimes the easiest way to solve a mystery is to sort the information into more manageable clusters.  For example, in winter, it is easy to see which trees are evergreen and which are deciduous.  We decided to begin with the nearest evergreen pine tree and quickly identified it as a loblolly pine.  A field guide helps narrow the range of choices within a type, or genus of tree.

 

 

There are several common species of pine trees in our area, so recognizing a pine by its clusters of long needles and its cones is a good start.  A field guide helps if you also want to know the tree’s particular species.

 

 

This usually involves counting the number of needles in each cluster, noticing the length of the needles and whether they are straight or slightly twisted, and noticing the tree’s bark and cones.  The Virginia scrub pine, Pinus virginiana, has short, twisted needles which are edible, usually in bundles of two.

 

 

Recognizing Common Local Trees

The easiest way to recognize trees is by their gestalt, their overall appearance.  Each genus has some obvious characteristics that you can learn to recognize from a distance.  It may be a tree’s overall shape and structure that you notice first, like the widely spaced branches punctuated with cones, on the very tall, thin trunk of a pine tree.

 

 

There are a limited number of evergreen trees and shrubs in our area that appear over and over again in parks, neighborhoods, and the woods.  Once you recognize them, you’ll see them everywhere!  First, notice whether the leaves are needles, scales, or broad leaves and whether the leaves appear glossy or dull.  That helps narrow down the possibilities further.

 

 

You may notice the ‘knees’ of a bald cypress tree, the red berries on a holly, or the dangling gumballs on a sweet gum tree.  Leaves, fruit, bark, nuts, cones, seed pods, and buds all offer clues we can learn to ‘read.’

 

 

You may recognize some trees, like the Eastern red cedar, by their fragrance.  Its rich evergreen aroma sings ‘Christmas’ to all of us who grew up with locally harvested red cedar Christmas trees.   Although Sassafras trees are deciduous, their twigs and bark still have that distinctive ‘root beer’ aroma in all seasons.

 

 

Tulip trees retain their woody, tulip-shaped seed pods through the winter.  You’ll notice them silhouetted against the winter sky.  Redbud trees have long thin papery seed pods that remind me of spring pea pods.

 

 

Sycamores, with their peeling white bark, have perfectly round fruit balls that dangle from long stems.

 

 

Looking for More Clues

Some trees may not offer any immediate clues once their leaves drop.  Young trees, that haven’t yet developed their mature bark, and may be too young to flower or fruit, can be especially hard to recognize.  This is when you may need to take a close look at their twigs and buds.  A twig is the youngest woody growth on the tree’s branches.

 

 

Twigs offer lots of clues to those who know what to look for.  Take a moment to look at a twig and its new buds closely.  Every detail is a clue:  color, shape, designs on the wood, and the scars where last summer’s leaves grew.

 

 

Even the number of vascular bundles within the leaf scar may be important in identifying the family, genus, and species, so have a magnifier handy to study the leaf scar closely.

The ‘dots’ on twigs are the lenticels, openings which allow air exchange through the thin bark so the tree can breathe without its leaves.  These dots, and any lines or other changes in texture or color, sometimes offer clues to help with identification.

 

 

After a general observation of the twig’s color and shape, notice whether the leaf scars are positioned opposite one another on the twig, whether they alternate, or whether leaf scars occur in a ring all around a twig.  The leaf scars often give up the most clues by their size, shape, position, and marking in and around them.   Also, notice whether smaller branches are positioned opposite or alternate with one another.  These are all clues needed to ‘key’ an unknown branch to determine its identity.

 

 

Finally, notice buds where flowers and leaves will emerge in the spring.  Notice their shape, color, and their positions on the older wood.  Do they emerge singly, or in a cluster?  What sort of scales, if any, cover the bud?

 

 

You may be able to identify an unknown tree just by studying its buds, because some, like dogwood and beech, have such distinctive shapes.  A cluster of buds at the terminal tip of a branch may indicate an oak tree.  The number and position of buds, and other details of their appearance, can sometimes help you determine the exact species of a tree.

 

 

When looking for clues on an evergreen, remember to examine all sides of the leaf and notice its aroma.  The color of the leaf’s underside and the presence and color of any tiny ‘fur’ or hairs on the leaf will help in identifying the tree.

 

 

Document Key Details With Photos

Taking photos of a tree’s details is helpful in eventually identifying it.  Take a photo that shows the entire tree from a short distance to reveal its structure.  Follow up with photos of the tree’s bark, a twig with buds, and any remaining leaves, fruit, pods or cones.  You can refer to these later and compare them to photos you find in books and online.

 

 

Using a Key

You will find a variety of dichotomous keys to help you identify trees in winter and in summer.  All lead you through a series of questions designed to help you narrow the choices and finally identify a tree.  These can become very complex, depending on how many types of trees are included.  Some handy field guides begin with a dichotomous key to help you navigate through the book.

 

 

Dr. Stewart Ware has compiled “A Winter Twig Key to Common Leafless Dicot Trees in the Williamsburg Area ( 2023).”  He has limited this key in scope to make it more useful for beginners.  It includes only deciduous trees.  This key will help identify the genus and common name for trees we encounter locally.  Use a good field guide to help identify the individual species of trees that belong to large genera like Quercus (oak) or Acer (maple).

 

 

Building a Repertoire

It takes time to build a repertoire of trees that we can easily identify, particularly those we can identify in winter.  Once you think you recognize a tree, look for additional clues to confirm your hypothesis.  Look at the fallen leaves below its branches.  Look for signs of fallen seed pods, cones, or nuts.  Notice what other trees grow in the area, especially those that have similar traits.  Try to find at least two to three clues to confirm your identification.

 

 

A single tree species has one accepted scientific name but may have one or many common names.  Botanists know trees by their genus name, like ‘Pinus’ or ‘Quercus’, and by their particular species name, like Pinus taeda or Quercus alba. It is helpful in many ways to know the botanical names of plants, even if we find these names awkward to pronounce.  This is the name that botanists agree to use in publishing information about each species.

 

 

When talking with family and friends, we’ll probably use the common name for trees, like ‘loblolly pine’ and ‘white oak.’  We are still using a common name for each tree’s genus (Pinus = pine and Quercus = oak) as well as a descriptor name to distinguish exactly which type of pine or oak if we know it.  A problem might develop when a particular species has a collection of different common names.  I might be discussing inkberry but you’re discussing Appalachian tea.  How do we know whether we’re discussing the same plant unless we both know the botanical name of the plant is Ilex glabra?

 

 

Several genera which are similar to one another in important ways are grouped into ‘families’ of plants.  As we learn more about the trees in our area, we may also learn about these families.  For example, we might learn that oak trees and beech trees belong to the same family, Fagaceae, along with chestnuts.  All these trees produce strong useful wood, support many species of wildlife, and give us delicious, high-protein nuts that indigenous Native Americans gathered for winter food.  They also need similar conditions to grow well.

 

 

We learn about trees one at a time.  The more we know about each type, the more easily we will recognize trees of the same genus wherever we go.  It is fun to recognize trees of all sizes and stages of growth from seedlings to mature trees.  The more species we can recognize, the more easily we’ll add new types to our repertoire.

 

 

From Garden to Arboretum

Our group eventually documented over 150 different woody taxa at the Williamsburg Botanical Garden and Freedom Park Arboretum.  We had help.  Dr. Donna Ware, retired professor and curator of the Herbarium at William and Mary, assisted our team in identifying many of the native trees, shrubs, and woody vines in the collection.  We documented our collection on Plants Map, and the Garden’s and Settlement’s collections were recognized by the Morton Arboretum in December of 2021.

 

 

The collection is now reduced after the removal of the Flowering Shrub Border this summer, but new trees will be added in the coming years.  You can find information about all of the various species online.  You can also take a virtual Tree Tour of the Garden, to learn more about the collection.  When you visit the WBG-FPA you will find many trees labeled with interactive QR tags that you can scan with your phone to learn more about each plant.  More Arboretum trees are labeled with QR tags in the nearby Settlement area.

 

 

As with so many things, the more you learn, the more connections you’ll notice.  Keep adding bits and pieces of information to your understanding of each genus.  What are its seeds like?  How does it support wildlife?  Are any parts of it edible or medicinal?  How does it look in spring and summer?  What colors do its leaves turn in autumn? Let curiosity be your guide. There are many beautiful books, field guides, and websites that help us build our knowledge about trees.

 

 

The more we learn, the more we will come to appreciate the many beautiful trees in our area.  And the more we appreciate each species, the more interested we become in nurturing, and perhaps even planting more trees in our community.

 

 

Many thanks to Drs. Stewart and Donna Ware for their assistance with editing this post,

and for their help in learning to identify trees in winter.

Appreciation to the Williamsburg Botanical Garden and Freedom Park Arboretum where some of these photos were taken.

 

 

All photos were taken in James City or York Counties by Elizabeth McCoy, Master Gardener Tree Steward, and former WBG volunteer.

 

For more information:

 

Core, Earl L. and Nellie P, Ammons. Woody Plants in Winter. West Virginia University Press. 1958.

Dirr, Michael A. Dirr’s Encyclopedia of Trees and Shrubs.  Timber Press. 2011.

Kershner, Bruce (and others). National Wildlife Federation Field Guide to Trees of North America. Union Square & Company. 2008.

Kirkman, L. Katherine, Claud L. Brown, and Donald J. Leopold. Native Trees of the Southeast.  Timber Press. 2007.

Mellichamp, Larry and Will Stuart. Native Plants of the Southeast. Timber Press. 2014.

National Audubon Society. Audubon Society Field Guide to North American Trees: Eastern Region. Knopf. 1980

Sibley, David Allen. The Sibley Guide to Trees. Knopf. 2009.

Wasowski, Sally and Andy Wasowski.  Gardening with Native Plants of the South. Taylor Publishing Company. 1994.

Watts, May Theilgaard and Tom Watts. Winter Tree Finder.  Nature Study Guild. 1970.

Nix, Steve.  “Winter Tree Identification”. Treehugger.

Ware, Stewart. “A Winter Twig Key to Common Leafless Dicot Trees in the Williamsburg Area.” JCCWilliamsburg Master Gardener Association. 2023.