Aspen of My Eye: A Profile of the Populus Genus

Aspens, or more specifically, aspen trees, are a beautiful species of tree found in many colder, more temperate regions within the northern hemisphere. They are members of the Populus genus, which contains a little over two dozen unique species of flowering deciduous plants – the most well-known of which is perhaps the Populus section Populus, more commonly referred to as aspens or white poplar trees.

While some people could live their whole lives without ever seeing a single aspen, the humble aspen is certainly one of – if not the most commonly found tree in North America and Canada today.

Origins of the Aspen Tree

Aspens are a fast-growing species of tree in North America although they can be found in Europe and in some parts of Asia as well. But where do aspen trees grow specifically, and what does an aspen tree look like, exactly?

According to the United States Forest Service, aspen trees are “medium-sized deciduous trees, commonly 20 to 80 feet in height, and 3 to 18 inches in diameter. Their bark is smooth, greenish-white, yellowish-white, yellowish-gray, or gray to almost white in color.” The unique coloration of their bark and leaves, in addition to the way aspens commonly grow together, can help create a beautiful forest landscape during particularly vibrant seasons in nature.

Aspens and their relatives are some of the most widely distributed trees on planet Earth and because of their extensive proliferation, especially amid locations where human beings lived and dwelled, the quaking aspen tree has some cultural significance for certain populations.

Cultural Uses & Associations

Before many of the discoveries of modern medicine, aspen bark and leaves were used as ingredients to treat various ailments like arthritis pain, back problems, and other sources of bodily discomfort. Because aspen trees contain salicin, a chemical that shares many qualities with aspirin, aspen bark and leaves have been used in salves or medicines to help reduce inflammation.

Additionally, the aspen tree has been a source of cultural significance since antiquity. Aspen bark and leaves were used by indigenous peoples for medicinal purposes, and in some cases, the trees themselves could be utilized in the construction of shelters. In ancient Europe, Celts seemed to revere aspen trees. They buried their dead adorned with aspen crowns in elaborate burial mounds, and the Celts also used aspen wood for shield-making purposes. According to folklore and mythology, people thought aspen shields had additional, mystic properties which would provide added protection from psychic or physical harm.

Even in modern times, it’s difficult to deny the beauty and mystical nature of the aspen tree – especially when you are able to visit them up close and even walk beneath their branches. They provide a suitable habitat for numerous species including bears, deer, elk, hare, moose, dozens of birds, as well as other small animals. They also provide tourists and foliage viewers with a spectacular view every autumn when the leaves change colors to a brilliant golden yellow that rivals the splendor of our nearest star.

American Aspen

The American aspen – otherwise known as Populus tremuloides – can be identified by its stunning white bark. They’re also commonly referred to as a quaking aspen or a trembling aspen due to the way the leaves flutter in even the gentlest breezes.

During the autumn months when the leaves have changed to their splendid yellow, a modest breeze can cause a whole forest of aspens to shimmer as one like tiny waves of a golden pond. The composition and shape of the leaves mean that, in addition to their visual splendor, aspen trees – with the help of the wind – can also sing a gentle, rustling song.

In the United States, most aspen trees are concentrated within aspen forests in Colorado and Utah, although they grow in scattered patches throughout many western states. Aspen trees are most commonly found at elevation levels between 5,000 and 12,000 feet above sea level.

Dense patches can also be found in Arizona, California, New Mexico, Wyoming, Idaho, and Montana as well. Aspens can also be found north of the Ohio River Valley and in parts of New England as well; they grow healthily in large swaths of forest throughout Canada from the Atlantic shore to the Pacific shore.

Because aspen trees are an aggressive pioneering species, they can thrive in certain areas like the Central Rocky Mountains where wildfires continually clear swaths of landscape for aspens to migrate into and thrive. And because they grow quickly and have relatively short life cycles for trees, aspens can play an invaluable role in the recovery of fragile ecosystems after wildfires decimate a landscape.

European Aspen

While the European aspen – Populus tremula – shares many similarities with its North American relative, they commonly grow in temperate, cooler climates around boreal regions of Europe (and in Asia as well). Like the American aspen, Populus tremula has a high ecological value and offers numerous species of mammals, birds, insects, and fungi suitable habitat.

Most European aspens today can be found in Sweden, Denmark, Lithuania, and Latvia. They can, however, also be found in places as far south as Northern Africa and as far east as Siberia, especially in areas with ample sunlight and moist (but well-irrigated) soils.

Aspens growing in Europe can reach similar heights to aspens growing in North America and elsewhere around the world. Their bark is similarly smooth with silver-gray hues; more mature aspens also develop diamond-shaped fissures in their bark known as lenticels. And much like the American aspen, the European aspen offers a brilliant and vibrant display of color every autumn when the leaves change from their docile green to a magnificent yellow-gold.

Best Times to View Aspen Trees

Autumn foliage enthusiasts might encourage newcomers to seek out the gorgeous and striking fall colors afforded by the changing leaves of aspen trees. Generally speaking, aspens at higher elevations will begin showing signs of changing leaf color soonest. The middle of September to early or middle of October is one of the best times to view aspen trees, especially in places like Colorado and Utah where there are aspen forests that can provide even grander spectacles.

In the springtime, aspen trees flower even before their leaves have emerged. Trees release their seeds which appear as tiny tufts of cotton that can blow around in the wind and look like snow in densely populated areas of aspens. While perhaps not as visually astonishing as autumnal aspens – they are still capable of inundating their landscape with beauty and majesty no matter what time of year it may be.

As people who are lucky enough to live near large swaths of aspens can tell you, there’s no bad time of year to view aspen trees. Their leaves and physical appearance are a delight all year round – just being able to get outside and walk around in nature with some of nature’s most gorgeous plants can be an invigorating and grounding experience.