How to Identify Cottonwood Trees

Cottonwood leaves and springtime pollen hanging off of tree.

Douglas Sacha / Getty Images

Cottonwoods are poplars native to North America, Europe, and western Asia. They usually occupy wet riparian areas in the East or seasonally dry creek beds in the West.

The name comes from the fluffy white cottonlike covering that appears when they produce seeds. There are three varieties of cottonwood that grow in the U.S.: eastern, black, and Fremont.

Cottonwoods are very similar to—and share a genus with—other true poplars and aspens. These trees like wet conditions and can even tolerate areas that see temporary flooding. When they are not surrounded by other trees or buildings, they are often spread out as wide as they are tall.

The wood from these trees is commonly used to make storage boxes, crates, paper, matchsticks, and plywood. It is easy to carve, making it popular with artisans as well. Herbalists sometimes use the buds and bark of cottonwood to treat aches and pains and skin irritations.

Identifying the Different Cottonwoods

The three cottonwood subspecies found in the U.S. are similar in some ways—such as their tendancy to grow tall (up to 165 feet)—and different in others—like leaf color and growing conditions. In general, cottonwood leaves are alternate and triangular, growing on flattened leafstalks. Their bark is yellowish-green and smooth on young trees but grayish-brown and deeply furrowed with scaly ridges in maturity.

Branches are usually thick and long. Since the wood is weak, they routinely break off, and foliage is uneven. Cottonwoods typically produce catkin flowers, though they vary in color.

Learn how to distinguish between the different subspecies, ahead.

Eastern Cottonwood

Eastern Cottonwood green leaves and fluffy white seeds.

raksyBH / Getty Images

The eastern cottonwood (Populus deltoides) is among the top 100 most common trees in North America. It's also one of the largest hardwood trees on the continent, even though the wood is rather soft. It's a riparian tree, meaning it grows along the banks of waterways and along the edges of floodplains. It occurs throughout the eastern U.S., as far north as southern Canada.

Males produce reddish catkins, while females produce yellowish-green catkins. Both males and females produce green capsule-looking fruits containing multiple cottony seeds.

Black Cottonwood

Fine teeth on the green leaves of a Black Cottonwood tree.

Rafael Medina / Flickr / CC BY-NC-ND 2.0

The black cottonwood (Populus balsamifera), also called the Western balsam poplar or California poplar, grows mostly west of the Rocky Mountains and is the largest cottonwood out West. It is distinguished by its leaves, which have fine teeth unlike those of other cottonwoods. Black cottonwood leaves may also have an ovate shape, and the leaves of mature trees may show a light rust color on the side facing the ground.

In terms of flowers, these cottonwoods produce yellow catkins on both male and female trees. The fruits of black cottonwoods are similar to those of the eastern cottonwood except that they have a hairy appearance.

Fremont Cottonwood

Green leaves on a Fremont Cottonwood tree in bright light.

OpsimathPhotography / Getty Images

The Fremont cottonwood (Populus fremontii), also known as the western cottonwood or the Rio Grande cottonwood, occurs in California east to Utah and Arizona and south into northwest Mexico. Named after 19th-century American explorer John C. Fremont, it is similar to the eastern cottonwood, differing mainly in the leaves having fewer, larger serrations on the leaf edge and in the flower and seed pod structure.

The Fremont cottonwood's fruit differs from other subspecies' in that it is light-brown and egg-shaped. It bursts into three to four sections to release its seeds. Both genders produce red catkins.