Poplar trees are tall, straight and deciduous.They live for about sixty years before becoming rotten. Most are well-known for their massive invasive root systems and vigorous ability to sucker or clone. Extremely hardy, the genus Populus contains species that grow from U.S. Department of Agriculture hardiness zones 1 to 10. All poplar trees start out life with thin, smooth, greenish white or greenish yellow bark; as they mature, the bark of some species becomes thicker, dark grey in colour and deeply furrowed. Poplar trees tolerate a range of conditions but grow best in moist, well-drained sites all over the United States.
Look for a group of trees with the same height, leaf shape, bark and tree trunk diameter.
Pick leaves from several trees, comparing them for similarity.
Look at the colour of the bark on several trees for similarity. Younger trees are smaller and are greenish white or greenish yellow in colour. Mature balsam poplars have grey-brown bark, while mature aspen and white poplar have greenish white or silvery bark.
Feel the bark on more than one tree with your hands for degree of smoothness. Younger trees have smooth bark.
Mature balsam poplars, black cottonwood and yellow poplar have rough, deeply furrowed bark, while the bark of mature aspens and white poplars is smooth and does not peel.
Poplar trees sucker, so they grow in large groves. In the spring, before the trees leaf out, they produce catkins. Male catkins and female catkins are borne on separate trees. Male catkins are 1 inch to 2 inches long while female catkins are longer, 2 to 5 inches long
Some catkins are filled with a cotton-like down that blows around, covering the ground, and causes allergic reactions in some people.