Birch Leaf Identification

The birch tree species native to North America typically grow in the eastern, northern and western part of the country, with only the river birch found in the southern part. These birch trees all have leaves with some similarities. However, between species, some not-so-obvious differences in the foliage can help in identifying the specific birch to which they belong. You can use the shapes, size and other facets of birch leaves to help you to recognize them, helped by a field guide to trees that contains descriptions and illustrations of these leaves.

Focus first on identifying a tree as a birch before you try to differentiate species and leaves. Birches are small to medium in size, with the tallest being the yellow, river and paper birches, which can grow to 80 feet. All birches have leaves that the tree sheds before winter, and the leaves grow on a twig in what a botanist would call an alternate pattern, with a leaf at each node on the twig rather than two at a node growing opposite one another. Birches have both male and female flowers on the same tree, called catkins, which develop during the course of the seasons and eventually produce the seeds that fall to the ground in late summer or beginning of autumn.

Determine the size of the birch leaf you are looking at, as the size can often help you tell what type of birch it is. Paper birch, for example, has 2- to 3-inch-long leaves that can be 2 inches wide. Bear in mind the length of the leaves of other common birches, such as yellow birch at 4.5 inches long, water birch at 1 to 2 inches long, sweet birch at 5 inches long, gray birch at 3.5 inches long and river birch at up to 3 inches long.

Use the birch leaf's shape to pinpoint the species. Keep in mind that paper birch, yellow birch and sweet birch possess an oval leaf with a rounded base and a pointy tip. Water birch leaves are somewhat similar, but are "fatter" in the middle. Note the triangular shape of the leaves of the gray birch, which taper to an elongated point. Study the shape of the leaves in your field guide as you seek to match them to birches you discover in the wild.

Identify birch leaves by some of their other features. Birch leaves have edges, or margins, which are serrated. Some have fine hairs on the stems and on their undersides, such as the yellow and river birch. The sweet birch leaf will give off a strong scent of wintergreen when you pick it and smell where it attached to the twig. Note the blue-green color of the blueleaf birch of far northern New England. In the fall, notice that yellow birch leaves will change from dark green to a brilliant golden yellow.