An evergreen tree retains its green foliage throughout the year, cycling its leaves over a period longer than a single growing season. This persistence distinguishes them from deciduous species, which shed all their leaves annually. While the term often brings to mind needle-bearing conifers, the group includes a diverse range of plant life. Identifying evergreens requires examining physical characteristics, moving from the details of the leaves to the structures of cones, bark, and the tree’s overall form. Observing these features allows one to accurately determine the species.
Foliage: Needles, Scales, and Arrangement
The leaves, commonly called needles, offer the most reliable starting point for identifying most common evergreens. The manner in which these needles attach to the twig is the first major distinction to observe. Pines, belonging to the genus Pinus, are uniquely identified by their needles growing in small clusters called fascicles, which are encased at the base by a papery sheath. The number of needles within a single fascicle is consistent for a species, such as bundles of five for Eastern White Pine or two for Scots Pine, which provides a straightforward identification clue.
Other major conifer groups, such as spruces and firs, have needles that grow individually along the branch. Spruce needles are typically four-sided in cross-section and sharply pointed. These needles are mounted on tiny, woody pegs called sterigmata, which remain on the twig after the needle drops, giving the branch a rough, abrasive texture. In contrast, a fir’s needles are flat and soft to the touch. Fir needles attach to the twig with a small, circular base, which leaves a smooth surface when the needle is removed.
A separate category of evergreens, including Junipers and Cedars, displays scale-like foliage rather than needles. These small, overlapping leaves lie flat and tightly pressed against the twig, giving the branch a braided or reptilian appearance. Broadleaf evergreens, such as Holly or Rhododendron, possess thick, leathery leaves with a distinct blade and petiole, much like deciduous trees, but they retain their leaves for more than one year.
Distinguishing Cones and Seed Structures
Reproductive structures provide another set of distinct physical markers, especially the female cones of conifers. The orientation of the cone on the branch is a simple but powerful distinguishing feature between two major genera. Fir cones are unique because they grow upright on the branch, resembling small candles, and they tend to disintegrate while still attached to the tree, scattering their seeds and leaving only a central spike.
Pine cones and spruce cones, by comparison, hang or droop downward from the branch once mature. Pine cones are generally woody and hard, with thick, rigid scales that make them stiff and non-flexible. Spruce cones are typically more cylindrical and have thinner, smoother scales that are somewhat flexible and can be bent without breaking.
Seed structures in non-cone bearing evergreens offer different clues. Junipers do not produce a true woody cone, but instead develop a fleshy, berry-like structure that is actually a modified cone with fused scales. Yews produce a single seed partially enclosed in a bright red, fleshy cup called an aril. These unique structures confirm the species identity when traditional cones are absent.
Analyzing Bark and Overall Tree Shape
The bark and the overall growth habit of an evergreen become more useful for identification as the tree matures and its lower foliage or cones are out of reach. Bark texture changes with age, but its mature form is highly characteristic of the species. Some evergreens, such as young firs, retain a relatively smooth, silvery-gray bark, while others develop deep vertical furrows or ridges.
Spruce bark often becomes furrowed and scaly, and the bark of some pines, like the Scots Pine, turns a distinct orange-red color on the upper trunk and branches. Other species have bark that exfoliates or peels in irregular plates, revealing mottled colors underneath, a trait seen in some Lacebark Pines. The texture can be described as plated, shaggy, furrowed, or smooth, and these descriptions are identifiers when combined with color.
Beyond bark, the tree’s silhouette and branching pattern, known as its growth habit, can narrow down the possibilities. Many firs and spruces maintain a tight, classic pyramidal shape throughout their life, with branches that sweep upward or horizontally. Conversely, many pines, such as mature White Pines, lose their lower branches and develop a more open, rounded, or irregular crown as they age.