Winter Identification Guide
Identifying deciduous trees and shrubs without their leaves can be challenging, but winter reveals unique characteristics. This guide explores key features like bark, buds, twigs, persistent fruits, and overall form to help you identify plants during their dormant season.
Winter ID Basics
Winter botany, the practice of identifying plants during their dormant season, relies on features other than leaves and flowers. While challenging, it's a rewarding skill that deepens understanding of plant structure and adaptation. Without the camouflage of foliage, the intricate details of bark, buds, twigs, and overall plant architecture become prominent.
Key features to observe include the texture and color of bark, the size, shape, and arrangement of buds, the characteristics of twigs (like pith and leaf scars), any remaining fruits or seeds, and the overall silhouette or branching pattern of the tree or shrub. Combining these observations allows for accurate identification even in the depths of winter.
Key features of a dormant twig include terminal and lateral buds, leaf scars, and lenticels.
Field Identification Tip
Start with the basics: Is the branching pattern opposite or alternate? This single observation can eliminate many possibilities. Then, look closely at buds and leaf scars with a hand lens – the details are crucial. Don't forget to step back and observe the overall shape and habitat.
Bark Characteristics
Bark is the protective outer layer of woody stems and roots. Its texture, color, and patterns change as a tree ages and can be highly distinctive. Look for characteristics like smoothness, peeling, ridges, furrows, plates, or lenticels (small pores).
Smooth Bark
Often gray, may have lenticels. Characteristic of Beech (Fagus), young Maples (Acer), and Aspens (Populus).
Shaggy/Peeling Bark
Peels in horizontal strips or vertical plates. Found in Birches (Betula), Shagbark Hickory (Carya ovata), and Sycamore (Platanus).
Ridged/Furrowed Bark
Has vertical ridges and grooves, often deep in older trees. Common in Oaks (Quercus), Ashes (Fraxinus), and Elms (Ulmus).
Plated/Blocky Bark
Breaks into squarish or rectangular plates. Seen in Flowering Dogwood (Cornus florida) and Persimmon (Diospyros virginiana).
Warty Bark
Characterized by corky, wart-like projections. Distinctive feature of Hackberry (Celtis occidentalis).
Muscle-like (Fluted)
Smooth gray bark with a sinewy, muscular appearance. Characteristic of American Hornbeam (Carpinus caroliniana).
Field Identification Tip
Bark appearance can vary significantly between young and mature trees of the same species, and even on different parts of the same tree (e.g., trunk vs. upper branches). Observe the bark on various parts of the tree for a complete picture. Color can also be affected by moisture (darker when wet).
Bud Characteristics
Winter buds contain the embryonic leaves, stems, or flowers for the next growing season, protected by scales. Their size, shape, color, texture (hairy, sticky, smooth), arrangement (alternate, opposite), and type (terminal, lateral, flower vs. leaf) are crucial identification features.
Bud Arrangement
Check if buds (and thus branches and leaf scars) are arranged opposite each other or alternate along the twig. Opposite arrangement is less common (remember "MADCap Horse": Maple, Ash, Dogwood, Caprifoliaceae, Horse Chestnut).
Opposite buds (left, e.g., Maple) vs. Alternate buds (right, e.g., Oak).
Bud Shape & Scales
Note the overall shape (pointed, rounded, conical) and the number/type of scales. Some buds have many overlapping (imbricate) scales, others have just two meeting scales (valvate), and some are naked (no scales).
Examples: Imbricate (Oak), Valvate (Dogwood), Naked (Witch Hazel).
Bud Size & Texture
Buds vary greatly in size. Compare terminal buds (at the tip) with lateral buds (along the side). Feel the texture - are they smooth, sticky (Horse Chestnut), or hairy (Magnolia)?
Large, sticky terminal bud of a Horse Chestnut.
Clustered Terminal Buds
Some trees, notably Oaks (Quercus), have a cluster of multiple buds at the very tip of the twig, rather than a single terminal bud.
Clustered terminal buds characteristic of Oaks.
Field Identification Tip
A hand lens (10x magnification) is invaluable for examining buds. Look for fine hairs, the number and arrangement of scales, and the presence of accessory buds (extra buds beside the main lateral bud). Terminal buds are often larger and shaped differently than lateral buds.
Twigs & Leaf Scars
Twigs themselves offer clues: color, thickness, presence of thorns or prickles, hairiness, and pith characteristics (the central tissue). Leaf scars, left where the leaf petiole detached, are particularly useful. Note their shape, size, and the pattern of bundle scars (dots within the leaf scar where vascular bundles entered the leaf).
Leaf Scar Shape
Scars vary from shield-shaped (Maple) to crescent-shaped (Ash) to circular or three-lobed (Oak).
Bundle Scars
Number and pattern of dots (vascular bundles) within the scar. Ash has many in a C-shape; Maple has 3-5; Oak has many scattered.
Pith
Cut a twig lengthwise to see the pith: solid, chambered (Walnut), hollow, or star-shaped (Oak).
Lenticels
Small pores for gas exchange on the twig surface. Can be prominent (Cherry) or inconspicuous.
Thorns/Prickles
Sharp projections. Thorns are modified stems (Hawthorn); prickles are epidermal outgrowths (Rose).
Stipule Scars
Scars left by stipules (appendages at the leaf base). A line encircling the twig is distinctive for Tulip Tree and Magnolias.
Field Identification Tip
Examine twigs from the previous year's growth, as they show the clearest features. Leaf scars are located just below the lateral buds. Use your hand lens to count bundle scars accurately. Some twigs have distinctive odors when scratched (e.g., Cherry, Sassafras).
Persistent Fruit & Seeds
Many trees and shrubs retain fruits, seeds, or cones through the winter, providing excellent identification clues. Look on the branches or on the ground beneath the plant.
Nuts & Acorns
Hard-shelled fruits. Acorns (Oaks), hickory nuts, walnuts, beechnuts are often found under trees.
Samaras (Winged Seeds)
Seeds with papery wings for wind dispersal. Found in Maples, Ashes, Elms, Tulip Tree.
Berries & Drupes
Fleshy fruits often persist, providing color. Examples: Holly, Viburnum, Sumac (fuzzy red clusters), Crabapple.
Pods & Capsules
Dry fruits that split open. Legume pods (Locust, Redbud), capsules (Catalpa), Sycamore balls.
Cones
Reproductive structures of conifers (Pine, Spruce, Fir). Also note cone-like structures on Birch and Alder.
Persistent Catkins
Dried flower clusters (catkins) may remain on plants like Birch, Alder, and Hornbeam.
Field Identification Tip
Look carefully both on the tree and on the ground directly beneath it. Animal activity can scatter seeds, but often remnants remain close by. Note the size, shape, color, and texture of any remaining fruits or their parts.
Overall Form & Silhouette
Without leaves, the overall shape (silhouette) and branching pattern of a tree become much clearer. Observe the general form: is it upright, spreading, weeping, or vase-shaped? Is the branching dense or sparse? Are the branches thick or slender? This "big picture" view can be very helpful, especially from a distance.
Excurrent (Pyramidal)
Strong central leader with branches diminishing in length towards the top. Common in many conifers (Spruce, Fir) and young Pin Oaks.
Decurrent (Spreading)
Trunk divides into several large, spreading limbs, creating a rounded or broad crown. Typical of mature Oaks, Maples.
Vase-Shaped
Branches ascend outwards from the trunk, resembling a vase. Classic shape of the American Elm.
Weeping
Branches hang downwards. Characteristic of Weeping Willow, Weeping Cherry.
Columnar/Fastigiate
Narrow form with upright branches growing close to the trunk. Seen in Lombardy Poplar, some Juniper cultivars.
Irregular/Twiggy
Lacks a defined shape, often dense and twiggy. Common in Hawthorns, some shrubby species.
Field Identification Tip
Observe the tree from a distance against the sky to best see its silhouette. Note the angle at which branches leave the trunk and how finely the twigs divide. Consider the typical habitat – is it growing in an open field or a dense forest? This influences shape.
Identifying Evergreens
While this guide focuses on deciduous plants, don't forget evergreens! Conifers (pines, spruces, firs, etc.) and broadleaf evergreens (holly, rhododendron, etc.) are easily spotted in winter. Key features for conifers include needle arrangement, length, and shape, as well as cone characteristics.
Pines (Pinus)
Needles are typically long and occur in bundles (fascicles) of 2, 3, or 5. Cones are woody with distinct scales.
Pine needles grouped in fascicles (bundles).
Spruce (Picea) & Fir (Abies)
Needles are attached singly to the twig. Spruce needles are often sharp, square in cross-section, and leave a peg when pulled off. Fir needles are typically flat, blunt, and leave a circular scar.
Single needles of Spruce (often sharp, 4-sided) vs. Fir (often flat, blunt).
Hemlock (Tsuga) & Yew (Taxus)
Needles are flat, attached singly, often with distinct white lines underneath (Hemlock) or a pointed tip (Yew). Yews have red, fleshy arils instead of woody cones.
Hemlock needles are flat with whitish bands underneath.
Cedar/Juniper/Arborvitae
Leaves are typically scale-like and overlapping, covering the twig, or awl-shaped (sharp and pointed, especially on young growth). Fruits are often small, berry-like cones (Juniper) or small woody cones.
Scale-like leaves characteristic of Arborvitae, Cedar, and mature Juniper.
Field Identification Tip
For conifers, needle arrangement (bundles vs. single) is a primary sorting feature. Check needle shape (flat, square, round), sharpness, and any markings. Cone shape, size, and whether they hang down (Spruce, Pine) or sit upright (Fir) are also important.