Quaking aspens, also called trembling aspens, are named for their leaves. Flat leaves attach to branches with lengthy stalks called petioles, which quake or tremble in light breezes. Quaking aspens regularly grow in dense, pure stands, creating a stunning golden vista when their leaves change color in the fall. The white bark is one identifying characteristic of this tree, but the bark is special for more than just its unique appearance. The bark layer of quaking aspens carries out photosynthesis, a task usually reserved for tree leaves. In winter, when other deciduous trees are mostly dormant, quaking aspens are able to keep producing sugar for energy. Deer, moose, and elk seek shade from aspen groves in summer. These same animals consume bark, leaves, buds, and twigs of quaking aspens throughout the year. Ruffed grouse are especially dependent on quaking aspens for food and nesting habitat. People use quaking aspens for fuel and to make paper, particle board, furniture, and hamster bedding. In terms of height, quaking aspens are relatively small. They are usually less than 50 feet (15 meters) tall in hardiness zones 2-7.