This tree is at the NC Botanical Gardens in Asheville, NC. http://www.ashevillebotanicalgardens.org/.
These trees propagate through root sprouts. Extensive clonal colonies of Aspen thrive in climates that are cold in the winter and stay cool in the summer. Each colony is composed of trees with identical characteristics for they share a single root structure. Each colony will turn color in the fall at the same time.
The leaves of the Aspen are nearly round and broadly oval. They are 2-6 inches long. They have fine teeth and the leafstalk is flattened. The bark is mostly smooth. It is chalk white to yellow-green. This tree can grow to 50 feet and a diameter of 3 feet. You will notice the leaves quaking in the wind and hear the sound of the leaves as they seem to dance.