It takes many years to form a forest. But over a longer period of time - 80,000 years, in fact - one special tree, and its several hundred quaking aspen clones, have formed a colony.

And very little has shook it ever since.

The Pando (in Latin: "I spread") is a "clonal colony" of single male quaking aspen, located in the Fishlake National Forest in south central Utah. This 6,615-ton giant is a legend; in fact, its root system is one of the oldest living organisms on Earth. And, as you may imagine, the Pando is the heaviest species in existence.

The Pando acquired its great mass when stems, or genetically identical trees, connected through a single underground root system of aspen clones. The roots sprout up through the ground in the form of trunks. The colony covers 105 acres of land, an area that doesn't compare to a typical root system, no matter the size of the tree.

With all those roots to keep up with, it's hard to imagine the quaking aspen's only "absolute" requirement is a lot of sunlight.

But despite Pando's massive size, its fragile, heart-shaped leaves and its sensitivity to the breeze explain why the species has its name. The leaves attach to branches on a long, flat petiole, so even a slight breeze gives the tree a trembling appearance.

But trembling is only part of its name. Pando is also a giant. It stands tall and strong against several harsh conditions, including fire. Forest fires, no matter how severe, actually encourage new aspen trunk growth because their damage allows sunlight to reach the forest floor. This asexual or vegetative reproduction process, also known as "root suckering," promotes outstanding longevity and prevents aspens from being in danger of going extinct. The Pando is the oldest known aspen colony, but 5,000- to 10,000-year-old clones are more common.

Black scars, or natural self-pruning marks, appear on the aspen's lower branches, but the species is identified by its smooth, white bark. Unlike birch bark, a species often confused with aspen, aspen bark does not peel. In the fall, aspens stand out with yellow and gold leaves - in rare occasions, red.

Spanning from locations such as New England, Canada, Alaska, California, Arizona and New Mexico, the quaking aspen can continue growing in winter while other trees go dormant. Its photosynthetic green layer that lies beneath the white outer bark allows the plant to synthesize sugars as well as help deer and elk survive harsh winters.

Its name suggests unsteadiness and even anxiety and apprehension. But after 80,000 years of existence, gradually spreading to several regions of North America, the quaking aspen has proved otherwise. With the exception of an occasional slight flutter of its leaves, nothing - even forest fires - seems to phase it. The quaking aspen is inspiring, beautiful and unique, and we can assume it's here to stay for many more thousands of years.