You would hardly believe white willow is a non-native tree in North America because it is so prevalent in the wild across the eastern United States and southeastern Canada. Taking its name from the color of its foliage, this tree is one to consider for growing in the wet parts of a landscape where few others grow. Differentiate it from other large willow species -- including peachleaf willow, weeping willow and black willow -- by learning about its particular characteristics.
Look for a tall willow tree. Some specimens of white willow grow close to 100 feet high. The white willow, a European native, averages between 50 and 80 feet tall with trunk diameters approaching 2 feet on the largest individuals, according to the "National Audubon Society Field Guide to Trees: Eastern Region."
Look for a tree with a rounded crown of branches and limbs that extend down to the ground. Under the tree, there will be leaves, sticks, twigs and broken branches. This tree accumulates lots of litter underneath it, as it has weak wood that is prone to breaking during storms. In the wild, you will notice the white willow rarely grows far from a source of water, such as a pond, swamp or stream.
Observe the color of the leaves. While the upper surfaces of the leaves are a grayish-green color and shiny, the undersides have a white appearance, which gives the tree its name. The undersides have a covering of fine hairs that also add to the whitish look of the leaves. In autumn, white willow leaves change to shades ranging from yellow to a bronze-yellow hue.
Measure the leaves on a white willow. They are narrow, possess finely serrated edges, and have a lance shape. The leaves are between 2 inches and 4 inches in length, but are no wider than ½ inch on average.
Examine the bark of the white willow. It is grayish-yellow and it contains many ridges. The stems on the branches are quite flexible and are a shade of yellow.