In the winter, identifying woody plants (trees and shrubs) takes a bit more work. Since there are no leaves on the deciduous plant you will need to know what the twigs, buds, bud scales, and bark look like. Here are some quick ways to identify woody plants in their winter conditions:
- Twig markings, such as the bundle and leaf scars, offer information as to how leaves are arranged when present. They can also tell you where the buds grow.
- The shape, size, color and texture of the buds. Flower buds can be arranged along the twig in an opposite and alternate manner. They are often much larger than leaf buds. Leaves form as either single or clustered end buds –found at the ends of twigs, or lateral buds (those along the twig). These can be sticking out (divergent) or closer to the stem (appressed). Most buds have protective scales that enclose the leaf tissue. The scars that are left from old buds are as distinctive as finger prints for each tree and shrub species. If no scales exist, the buds are considered naked.
- Look to the branch arrangement. All trees and shrubs have either opposite, whorled or alternate branching. Alternate branching means that the twigs and buds grow off a main branch one at a time. Whorled branches or buds have three or more radiating from a single node, while opposite branching is where twigs and buds grow off a main branch in pairs. Maples, ashes and dogwoods are examples of opposite branching. Examples of alternate branching would be cottonwood, oak and cherry trees.
- With experience, the bark of the tree or shrub can be used for identification although the appearance may change with age and growing conditions. Look for differences in color, thickness, texture and patterns of peeling. For example, paper birch and cherry peel horizontally in large strips.
Odor. Scratch & sniff! The identity of certain plants can be found just by scratching off a bit of the outer bark and giving it a whiff. For example, salal has a wintergreen flavor. Yellow birch also smells like also wintergreen, which is useful in determining the species. Wild cherry has a bitter almond scent, and maple bark also has a recognizable smell.
Before setting out for a winter walk, make sure to bring along a good field guide to assist in figuring out what is what. Some of my favorites include Trees of Washington, Winter in the Woods: A Winter Guide to Deciduous Native Plants in Western Washington, and The Tree Identification Book by George W.D. Symonds.
By Jim Freed, WSU Extension Forest Products Specialist
Glossary of terms for winter shrub and tree identification
Alternate – Twigs and buds are arranged around the stem in an uneven pattern.
Bud scales – Small leaves that grow around outside of the bud. If there are no scales, the bud is considered “naked.”
Bud scale scars – Tiny dots that can be seen inside the leaf scar after the leaf falls.
Lateral buds – Buds that grow on the sides of a twig or branch.
Leaf scars – Scars left on the twig after the leaf falls.
Lenticels – Small, lighter colored spots on the back of the twig. They are tiny openings the allow air in & gas out.
Nodes – Leaf bearing joints of the twig.
Opposite – Twigs and buds that grow in pairs opposite each other on the stem.
Pith – The spongy center tissue of the twig.
Phloem – The living tissue (the innermost layer of the bark) that carries organic nutrient to all parts of the plant where needed.
Terminal buds – Buds that are found on the tips of a stem or branch.
Vascular bundle scars – Where the xylem entered the leaf and phloem entered the twig
Whorled – Where three or more twigs or buds come from the same area of the stem
Xylem – The xylem transports water and soluble mineral nutrients from the roots throughout the plant.