By Jason Beale, Abbott’s Mill Nature Center Manager
The adult Naturalist Certification Class at Abbott’s Mill is focusing on Winter Tree and Shrub ID this month. While it may seem strange to spend time studying deciduous (leaf-losing) woody plants during their dormancy, it helps sharpen your botany skills throughout the rest of the year. The lack of leaves takes away obvious clues and demands that the naturalist stick to branching patterns, buds, leaf scars, and bark.
Branching patterns are probably the best starting place by classifying the tree as opposite (twigs and buds directly across from one another) or alternate (twigs and buds occurring in zig-zag pattern).
Opposite branching trees and shrubs are represented by just a few species that can be remembered as: MADCap Buck, where M = maple, A = ash, D = dogwood, Cap = caprifolicaceae (the family composed of the honeysuckles, elderberries, and viburnums), and buck for the buckeye (aesculus spp).
Buds can be categorized by number (single, paired, or clustered), shape (rounded, pointed, etc.), scales (single, double, overlapping, or no scales). Below is a somewhat pointy bud cluster, typical of this southern red oak and other red oaks. White oaks tend to have more rounded buds in their clusters. Next is a tuliptree with its two-scaled “duck bill.”
A Leaf Scar is where a leaf stem (petiole) was attached during the growing season. They can be of a variety of shapes from circular, “U’s” or “V’s”, or unique. The “Monkey Face” of the black walnut is a classic example.
Bark is a useful for ID in any season. Common descriptions include smooth (ex. holly and beech), checkered (persimmon), rectangular (white oak), furrowed (ash, hickory, and tuliptree), and an variety of others. Black cherry bark is a good example of a mnemonic or memory-jogger. The dark, flaky bark has been described as “Burnt Cornflakes”, “B” for black and “C” for cherry.
I would encourage you to look closer at the trees and shrubs around your residence. Not only will your identification skills grow, but you may notice how birds like Brown Creepers investigate species with exfoliating or peeling bark for dormant insects and what tree species Yellow-bellied Sapsuckers favor for drilling their wells.