Tree identification by leaf shape
Needle-like leaf
Needle-like leaves are found on three types of trees: pines, firs and spruces. Needle-like leaves are long and very narrow with a sharp point at the tip. These needles grow in bundles, often arranged in rows along the twig. The needles are flexible, often dark green and may be waxy or have a white band along the bottom of each needle. You’ll also notice that pine needles grow in bundles of two to five; spruce needles grow individually; while fir needles tend to grow in groups of two or three.
Scale-like leaf
If you are looking at a tree that has leaves that appear like overlapping scales or fish scales, the tree might be a juniper (Juniperus species). Junipers can be both trees and shrubs.
Is the tree you are looking at bearing needle-like leaves?
Broadleaf
Broadleaf trees, as the name suggests, have large leaves. Leaves are flat, and have a wide surface area that is helpful for collecting sunlight for photosynthesis. The underside of broadleaf leaves often has a white or grayish color to it due to the accumulation of a waxy substance that covers the leaf to prevent water loss (it also gives broadleaf leaves a glossy sheen). The surface of the leaf is covered by cells called the cuticle, which forms an additional barrier against water loss. Broadleaf leaves are shed in winter, except in places where there is not a freezing season. Broadleaf trees do not produce cones or needles; they produce flowers instead! If you see flowers on your tree, then it is almost certainly some type of broadleaf species.
Compound leaf
A compound leaf is a single leaf that has multiple leaflets on it. Each of these leaflets is considered a leaf in itself, and many look like the leaves you are already familiar with. The black walnut tree, for example, has very large compound leaves with eleven to fifteen pointed oval leaflets per leaf. The ash tree can have as few as five or up to eleven leaflets of varying shapes, but they all have the same tooth pattern along the edges.
There are two ways you can tell if a leaf is a compound leaf:
- A compound leaf will have multiple petioles (the thing that attaches the leaf to its branch) coming out of one bud, meaning each petiole will attach itself to each individual component of the compound leaf. Consider our previous two examples:
- The black walnut tree’s long stem connects the entire set of leaves together at once so they look like one big unit instead of several smaller ones
- The ash tree’s individual leaflets are connected at their base by short stems
Identify trees by their leaves.
You can identify a tree by its leaves, but it might be trickier than you think. For example, if you see a tree with needle-like leaves, is it a pine or a spruce? Needle-like leaves can mean the tree is a pine, spruce or fir (eg. white spruce, red pine), or even larch. If the leaves are scale-like, they’re probably on either a juniper or yew. Broadleaf trees have…well…broad leaves and include elms, maples (including sugar maple and red maple) and oaks.