Scientific Name
Acer griseum
The paperbark maple is a member of the trifoliate group of maples, meaning that instead of a single leaf arising from each bud, which is the case for most maple species, they have a three-part compound leaf. This is unusual because ordinarily all the species of a tree genus will have either simple or compound leaves. As the country with the highest diversity of maple species, China is the native territory for most trifoliate maples, including the paperbark maple. Because this tree comes from central China, it developed the natural cold hardiness required to flourish in Denver’s climate.
The outstanding ornamental attribute of paperbark maple is its copper/cinnamon-colored peeling bark that begins to form even on young branches. Older trunks are notable for retaining the somewhat transparent bark curls for a long time. The leaflets of the paperbark maple are bluntly toothed, dark green on the top and have a duller green below. In the fall the foliage on some trees will turn a bright red to orange color. The fruit is a hanging, double-seeded structure known as a samara which is a hallmark of all maple species. It features a thin wing on each seed, with the pair typically arrayed at a 45-degree angle. Paperbark maples are relatively small trees that usually don't exceed 25 feet in height with a somewhat smaller canopy spread, although the trunks can become rather stout with age. The Regis campus has two paperbark maples, located near each other north of West Hall. The larger of the two has a trunk diameter of nine inches, which is the third largest in Colorado and listed as a Colorado state champion.
The paperbark maple was first brought from China to England by the famous British plant explorer E. H. "China" Wilson in 1899 and reached the Arnold Arboretum in Boston a couple years later. Very few additional germplasm collections of the species were subsequently made until the current century when it was realized that most trees in cultivation were offspring of the original Wilson plants, thus resulting in a potentially unhealthy lack of genetic diversity.