Aspen trees have rough gray-white bark and large circular leaves with serrated edges. They are medium-sized deciduous trees. The most frequent aspen trees in North America are the quaking aspen (Populus tremuloides) and bigtooth aspen (Populus grandidentata). The spreading root system of aspen trees generates new clone trees, which is unusual. Aspens may be found growing from Alaska to Mexico, all the way north and south.
The most widely distributed tree in the United States is the quaking aspen. In even slight breezes, quaking aspen has thin, rounded leaves that rustle. It is a tall, straight tree with thin, rounded leaves. The aspen trees quake or tremble as a result of this action. A quaking behavior is also seen in the closely related European trembling aspen tree (Populus tremula).
In North America, aspen trees grow alongside coniferous trees. USDA zones 2 through 8 are home to aspen trees, which are cold-hardy trees. When the tree suckers sprout from roots, you’ll often find younger aspen trees growing alongside adult aspens. The different species of aspen trees are identified in this article. Aspens growing in parks and forests can be recognized by descriptions and images of aspen leaves and bark. You can distinguish aspen trees from birch trees using this information.
Aspen Tree Facts
The genus Populus includes aspen trees, which are flowering trees. The straight, slender trunks, circular leaves, and catkins of dangling flower spikes that characterize aspens are noteworthy features. Aspens reach a height of 20 to 80 feet (6 to 24 meters) and a width of 20 to 30 feet (6 to 9 meters).
Aspens are connected to cottonwood trees and poplars since they belong to the Populus family. Trembling poplar, white poplar, and American aspen are some of the quaking aspen tree’s more popular names.
Aspens may grow to be around 2 feet (60 cm) per year. They have a high multiplication rate. Aspens grow in a chilly environment, and this has no bearing on their growth. Between 40 and 150 years, aspen trees survive. Their rhizome root system, on the other hand, can live for thousands of years. Suckers develop, mature trees perish, and fresh trees sprout.
Aspen Tree Leaves
On the right, autumn leaves on the aspen tree are smooth and glossy green round leaves with a pointed tip that range from 1.5″ to 3″ (4 – 7.5 cm) in diameter. The leaves of some aspen species are oval with toothed or slightly lobed borders. By flattening their stems (petioles), aspen leaves are able to attach to trees. Aspen tree leaves turn brilliant golden yellow, orange, or bronze-red in the autumn.
The leaves make a quaking appearance and produce a rustling sound. The flat leaf is fastened to the short, flattened stems at right angles. Aspens quake even when the slightest of breezes hits them due to their rapid growth. A quiet, tranquil rustling sound is produced by this leaf action.
Individual species can be identified by differences in leaf shape between native aspen trees. Leaf margins with tiny teeth, for example, may be seen on the quaking aspen tree. The bigtooth aspen tree, on the other hand, has jagged leaves owing to its larger, more spaced teeth.
Quaking aspen, trembling aspen, and trembling poplar are all names for the tree that come from aspen leaves. With the slightest breeze, leaves on aspen trees tremble and rustle. Aspen leaves take on the appearance of thousands of fluttering butterflies as a result of this effect.
Aspen Tree Bark
Aspen tree bark is smooth and greenish-white when mature, but becomes rough and fissured as the tree grows. A close-up picture of aspen tree trunks with smooth greenish-white bark Aspen bark has a thin appearance with horizontal splits and black hairy patches, according to closeup photographs.
Aspen trees are commonly mistaken for white birch trees because of their silvery-white appearance. There are a few differences between aspen tree bark and other types of bark. Chlorophyll, which makes aspen bark photosynthetic, is the first component to give the greenish hue. Butterflies, deer, beaver, moose, and elk all eat aspen bark.
Aspen Tree Trunk
The long, slender straight trunks of aspen trees are easily identifiable. Aspen tree trunks are mostly branchless halfway up, measuring up to 80 feet (24 meters) tall and 8 feet (2.4 meters) in diameter. The small crown of the towering aspen trees flutters continuously.
Aspen Tree Roots
Aspen roots, which stretch up to 30 feet (9 meters) from the tree trunk, are robust, fast-spreading rhizomes. Only about 1 foot (30 cm) below the soil’s surface do aspen tree roots grow. Aspen roots have the potential to damage foundations due to their fast, spreading nature.
Invasive aspen roots create new shoots or suckers all the time. Roots that are left in the soil continue to develop even if the trees are removed. Planting quaking aspens in a garden landscape should be at least 30 feet (9 meters) away from nearby dwellings.
In early summer, aspen seeds seem to be cotton-wool tufts that have been blown off the trees. Aspen tree seeds develop after the aspen blooms have gone. Dangling catkins up to 2″ (5 cm) long produce flowers and seeds.
How to Identify Aspen Tree
The upright, slender form of the aspen tree, small round tooth-edged leaves on the tips of long branches, and grayish bark are some of its identifying features. The shaking leaves that make the tree seem as if it’s trembling are a sign of aspens. Aspens, for example, prefer to develop in thickets rather than solitary trees.
Individual species can be identified by comparing the leaves of aspen trees. In comparison to the quaking aspen tree, the bigtooth aspen tree has bigger leaves with coarser serrated margins. The leaves of the European aspen tree, on the other hand, are more rounded.
Aspen Tree vs. Birch
Aspen trees (left) and birch trees (right) have a lot in common with each other. Although both species have lengthy, straight white stems, they are from distinct families. Populus and Betula are the genus names for aspen and birch, respectively. The type of bark and leaves, for example, are different between aspens and birch.
As the fast-growing tree reaches maturity, aspen bark becomes rough and fissured. Unlike aspen trees, which have thick bark and are papery, birch tree bark is thin and peels easily.
The leaves of aspen trees are generally rounder and shorter than those of birch trees, with less serrated borders. Flat, rounded leaves with a pointed tip and serrated edge on aspen trees are easy to find. Compared to birch leaves, the leaves appear broader, rounder, and shorter. They are usually more finely cut. Lanceolate leaves, rather than flat aspen leaves, are found on birch trees.
Types of Aspen Trees (with Pictures)
Let’s take a closer look at the various types of aspen trees.
Quaking Aspen Tree (Populus tremuloides)
The main aspen species in North America is the quaking aspen tree (Populus tremuloides). Quaking aspen trees reach 20 to 80 feet (6 to 24 meters) in height and width. Due to their fluttering leaves that make a rustling sound, quaking aspen trees are easy to identify. The quaking aspen tree has a lengthy, slender pale trunk with black spots, similar to other aspens. A rounded crown is created by long petioles with rounded shiny green leaves. Quaking aspen tree leaves have a pyramidal growth pattern from afar.
The American aspen or quaking aspen tree is also known as trembling poplar because of its glimmering leaves. The tree is also known as golden aspen due to its spectacular golden autumn foliage. The gray-white bark on the slender trunk gives it the name “white poplar.”
The shallow spreading roots of fast-growing quaking aspen trees spread the tree. The rhizome roots give birth to new trees. A mature aspen may quickly be surrounded by a network of young cloned trees. Quaking aspens develop in groves due to their unusual growth pattern.
Quaking aspens have the accolade of being the world’s biggest plant due to their vast root system. A single quaking aspen tree in southern Utah has roots that span over 100 acres. The tree’s aspen roots are estimated to weigh 14 million pounds (6 million kilograms). Utah’s state tree is the quaking aspen. Quaking aspens only survive for around 50 years in residential areas.
Aspens that tremble
The rumbling leaves of Populus tremuloides make a fascinating sound. A flattened petiole and a huge round brilliant green leaf give the trembling leaf effect. Quaking aspen leaves flutter in the lightest of breezes. Aspen leaves look like butterflies because of the contrast between the brilliant upper surface and the dull under surface.
Growing American aspen (Populus tremuloides)
USDA zones 2 through 8 are appropriate for quaking aspen trees. When planted in full sun, the aspen tree grows quickly. Aspens prefer rich, well-draining soil that is constantly moist and thrive in them. Because of the strong, invasive root system of quaking aspens, it’s recommended to avoid planting them near buildings.
Quaking aspen tree leaves
The surface of Populus tremuloides leaves is smooth, flattened, and pointed at the apex. Fine tooth-like serrations border the leaf’s margins. In the autumn, aspen leaves turn gold, yellow, or orange. They are a brilliant green color. The aspen leaves, which may reach 3 inches (7.5 cm) in diameter, are very firm.
Quaking aspen trees have a lovely look with their golden yellow fall color. The brilliant yellows and oranges contrast with the evergreen foliage of spruce, conifers, and fir trees because the trembling American aspens grow in coniferous woods.
Quaking aspen tree bark
Quaking aspen bark has a greenish tint and is smooth and silvery-gray. The bark gets rougher as the trembling aspen matures. It has a fissured look with black horizontal scar-like stripes. The capacity of quaking aspen bark to photosynthesize is a unique characteristic.
In North America, wildlife eats quaking aspen tree bark. The bark will be stripped for food by elk, deer, and moose, resulting in visible vertical marks on the tree.
Bigtooth Aspen Tree (Populus grandidentata)
The bigtooth aspen tree has rough oval to ovate dull green leaves with irregular serrations along the margins. The bigtooth aspen tree (Populus grandidentata) has bigtooth bark. The olive-green color of bigtooth aspen tree trunk bark is smooth and thin.
The deep vertical fissures in the aspen bark give it a rough, dark-gray appearance. The hugetooth aspen tree, like the quaking aspen, trembles in the slightest breeze. In Latin, the botanical name Populus grandidentata means “big toothed.”
Between 60 and 80 feet (18 to 24 meters) tall, bigtooth aspen trees grow. The irregular, slender rounded crown and straight trunks of bigtooth aspens distinguish them. The bigger leaves of bigtooth aspens distinguish them from quaking aspens.
Only 50 to 70 years old bigtooth aspens survive. Before the rough grooves form, the aspen tree trunk is covered with smooth bark for the first 30 years.
Bigtooth aspen tree leaves
Bigtooth aspen leaves are up to 3.5 inches (9 cm) broad and 4 inches (10 cm) long. The ovate shape and pointed tip of each thin leaf blade. Teeth are unevenly distributed along the leaf margins. On top, the bigtooth aspen leaves are dull green, while beneath them is pale green.
In comparison to the quaking aspen tree, bigtooth has broader leaves. In the fall, bigtooth aspen leaves become a vibrant gold or yellow color. This aspen species is usually the last of its kind to turn colors in the fall. In contrast to evergreen coniferous trees, this golden yellow foliage looks fantastic.
European Aspen Tree (Populus tremula)
The European aspen tree has round, flattened green leaves with a coarsely serrated border. In the springtime, observe for smooth pale greenish-gray bark, a broad crown, and dangling flowers on bare branches to identify European aspens. European aspen leaves flutter and shudder in moderate winds, much like the quaking aspen tree.
Populus tremula catkins are 130-foot-tall (40 m) giant aspen trees that grow 33 feet (10 m) broad. Because of their rounded leaves that don’t have a prominent tip, you can tell European aspens from other common aspens. In addition, quaking aspens and bigtooth aspens have coarser serration.
When it’s windy, the European aspen’s botanical name alludes to its quaking nature. Common aspen, Eurasian aspen, and quaking aspen are some of the other names for this species.
A fastigiate (columnar) cultivar of the European aspen tree, Populus tremula ‘Erecta’
European aspen tree leaves
The blades of Populus tremula have coarsely serrated margins and a circular form at the end of flattened petioles. The broadleaves are approximately 3 inches (7 cm) long. The leaves of this species of aspen dance and flutter in light breezes, producing a rustling sound. In the fall, European aspen tree leaves turn a brilliant yellow or orange-red.
Chinese Aspen Tree (Populus adenopoda)
The Chinese aspen tree has smooth, grayish-white bark and ovate leaves. It is a medium to large deciduous flowering tree. This aspen tree can grow to be up to 100 feet (30 meters) tall. As the tree grows older, the Chinese aspen bark becomes gray, rough, and split like that of many aspens. The Populus adenopoda is a Chinese species with the popular name “Adenopoda.” The aspen thrives in hilly areas there.
Chinese aspen tree leaves
Aspen leaves with a lustrous green finish are round, orbicular, or ovate in shape. Some species have lanceolate leaves with smooth edges, whereas others have fine serration along the round leaf margins. In the autumn, the dark green aspen leaves take on a brilliant yellow color.
Korean Aspen Tree (Populus davidiana)
Green orbicular-shaped leaves and smooth, grayish-white bark distinguish Korean aspen (Populus davidiana) leaves. On the aspen tree, the thick foliage creates a rounded crown. Long dangling blooms emerge first, followed by little cottony seeds in early summer. Korean aspen trees can grow up to 25 meters (82 feet) tall.
Korean aspen tree leaves
The base of Korean aspen leaves is broad and rounded, while the tip is narrow and pointed. Aspen leaves turn green in the autumn and mature to golden yellow. They are red when young, then green. Their rounded blades are finely-serrated, like those of other aspen tree leaves.
Japanese Aspen Tree (Populus sieboldii)
The Japanese aspen tree, Populus sieboldii, grows at a fast pace and reaches 65 feet (20 meters) in height. The foliage is flat, rounded toothed leaves, and the bark is smooth grayish-white. The characteristics of Populus sieboldii are: It’s best not to plant Japanese aspen tree within 40 feet (12 meters) of a building because of its spreading, invasive roots. Aspen roots have the potential to damage foundations and sewage lines.