Twigs, buds, bark help identify trees in winter

A walk through the Big Trees Forest Preserve in Sandy Springs with my fellow Georgia Botanical Society members last weekend brought much-needed relief from cabin fever — and a greater appreciation of buds, twigs, bark and other tree features that are more prominent during winter.

The outing was billed as a “casual stroll among deciduous hardwood trees and shrubs that will give us plenty of opportunities to practice our woody plant identification.”

As our leader Ellen Honeycutt noted, leaves are by far the easiest ways to identify trees in spring and summer. But in winter, most deciduous trees have dropped their dead leaves (exceptions are American beeches, hornbeams and some oaks, which may hang on to some of their brown, lifeless leaves). Leaves being absent, twigs, buds, bark, leaf scars and other traits become the best identification aids, she said.

One way to start narrowing down a leafless tree’s identify, she explained, is to notice its twig and branch patterns. Twigs and branches that alternate positions as they grow from the trunk is a trait of oak, cherry, hickory, birch, sycamore and some other trees. Trees whose twigs and branches grow opposite from each other, like the arms of our bodies, include maples, ashes and dogwoods and others.

To further narrow the ID process, examine the shapes, sizes, colors and textures of buds, which vary from species to species, and their locations on twigs. Buds become flowers and leaves. Flower buds are often much larger than leaf buds, which form as either terminal buds at the ends of twigs or lateral buds along the sides of twigs.

Each species also has its own characteristic bark. Some species, such as sassafras and sweet shrub, also have tell-tale odors that reveal their identities.

A free tree ID guide can be found here: .

IN THE SKY: From David Dundee, Tellus Science Museum astronomer: The moon will be full on Wednesday — a blue moon. By definition, a blue moon is the second of two full moons to fall within a single calendar month. A second blue moon will occur in March. Mercury, Venus and Saturn are low in the east just before sunrise. Jupiter and Mars rise in the east just after midnight.