Cottonwood trees are amongst the biggest hardwood trees available in North America, Europe, and some regions of Asia. They are an important part of many forest ecosystems across the globe. Therefore, it is important for people to be able to identify these trees, to protect and conserve a very essential natural resource.
Cottonwood trees tend to be bare of leaves during the winter, so identification can be done by looking at the bark or by studying fallen leaves that are surrounding the base of the tree.
Cottonwood trees are one of three species in the section Aigeros in the genus Populus. These trees are native to North America, Western Asia, and Europe. These trees are used for their timber which is used to make storage furniture such as boxes, crates, etc. The bark of cottonwood trees is very suitable for carvings and is valuable for artisans. These trees are also very important in maintaining the well-being of numerous wild animals, birds, and insects. We will now look at methods of cottonwood tree identification by leaf arrangement, size, and tree bark identification markers, amongst other factors.
How to Identify a Cottonwood Tree
The easiest way to distinguish one cottonwood species from another is to study the leaves and bark. However, all cottonwood species have some characteristics that they share in common, which can be used to separate cottonwoods from other trees:
- Height: Mature cottonwood trees can grow very high reaching up to 100 feet in height.
- Crown: The lowest branches of a mature cottonwood tree may be too high to reach, making it difficult to climb. In wide open spaces, the crown can be as wide as the height of the tree.
- Location with Water: Cottonwoods love to grow in areas where the moisture content is relatively high. These include the banks of rivers, streams, ponds swamps, etc. They can even survive for short periods completely standing in water, such as during floods.
- Branches: The branches spreading out from the trunk of a cottonwood tree are usually very thick and long. If the branches appear to be thin or short, the tree is probably not a cottonwood. The wood of a cottonwood tree is usually weak, and branches break routinely due to this. This means that the foliage of a cottonwood tree is often uneven and rugged.
Let us now see how we can identify one cottonwood species from the other by studying their leaves and bark.
Eastern Cottonwood Tree Identification
Eastern cottonwoods are native deciduous trees that are widespread near river banks and low-lying areas. Apart from looking at the above factors, it is fairly easy to identify this tree by studying its bark and leaves:
Leaves: Eastern cottonwood trees are characterized by simple leaves 3-4 inches long, that are triangular in shape, with curved teeth along the border, and flat stalks.
Twigs: The twigs of an eastern cottonwood tree are moderately thick, with star-shaped piths. These may either be gray or green in color. The ends of the twigs are usually covered with a brown balsam-scented resin.
Fruits: Green capsule-like fruits grow on the tree, which contain numerous cottony seeds within them.
Flowers: Red and greenish flowers, grow on eastern cottonwoods. However, the flowers are dioecious, i.e., the type of flower growing will depend upon the gender of the tree.
Bark: On young trees, the bark is thin and smooth in texture. The color is usually grayish green in color. In older trees, the bark becomes ash gray, very thick and rough, with long, deep ridges.
Black Cottonwood Tree Identification
This species is the tallest and largest of the three cottonwoods, and can reach up to 150 feet in height. The following points should help you to identify a black cottonwood.
Leaves: The leaves of a black cottonwood tree grow alternately in a pale green shade, with a leaf size of 2-2.5 inches in length and width. The leaves may be triangular or ovate in shape, with a fine serration on the borders. Leaves of mature trees can display a light rust color on the side facing the ground.
Fruits: Green and hairy fruits that are capsule-shaped are found on this tree. The fruits contain many cottony seeds.
Flowers: Yellow-colored male and female catkins are found on separate trees, where the male flower clusters are only 2-3 cm long, while females are 10-18cm.
Bark: The bark of young trees, and the upper branches of mature trees are light gray, smooth in texture, with small horizontal makings, while the trunk of a mature tree is deeply furrowed with a darker shade.
Western Cottonwood Tree Identification
Also known as Fremont cottonwood or Rio Grande cottonwood, this tree is commonly found near water bodies of arid regions. These trees have a widespread foliage that can extend to 5 feet in diameter. Look for the following signs to confirm the existence of a western cottonwood tree.
Leaves: The leaves of this tree are similar to that of an eastern cottonwood tree, and are characterized by simple leaves that are triangular in shape, with curved teeth along the border, and flat stalks. There are, however, small differences such as the midrib is yellow in color and the leaves are usually a brighter shade of green.
Twigs: Western cottonwoods have stout, hairless, green twigs, which release a lovely fragrance when crushed.
Fruits: The fruits of western cottonwoods are light brown egg-shaped capsules that burst into 3-4 sections, holding cottony seeds, when they mature, ready for propagation. This is usually only seen during fall.
Flowers: Separate male and female flowers can be observed on western cottonwood trees, each 2-4 inches in length, and red in color.
Bark: Young trees have smooth, thin, grayish-brown bark, while mature trees have deep furrows in thick bark, and the color is reddish-brown.
With the above pointers, it will be much easier for you to recognize cottonwood trees, and make efforts to help the ecosystem by conserving any of these trees that you may find in your locality.