Virginia Roundleaf Birch
Virginia Roundleaf Birch may be the rarest native U.S. tree species still existing in the wild. The only known natural population grows along a creek in Smyth County in southwest Virginia. These plants were first observed in the early 1900's, but due to confusion about their location, later attempts to find them were unsuccessful. For several decades it was feared that the species was extinct. Finally in 1975 a few dozen plants were located.
After the rediscovery, various government and private organizations cooperated in an effort to preserve the species. Seeds were collected from the existing trees and planted in other selected areas, and by 1992 a total of more than 1400 plants were growing at 20 different locations. Seeds and plants were also supplied to arboreta, university researchers, and other interested parties. Because of the success of these efforts, in 1994 the U.S. Fish and Wildlife Service changed the official status of the species from Endangered to Threatened. As a result, it is now possible for you to grow this plant on your own property.
The tree, which is also called Ashe Birch, can reach a mature height of about 40 feet. It has a narrow trunk and an oval crown of many slender branches. Unlike most birches, it has dark bark and distinctly rounded leaves. Both leaves and bark release a wintergreen scent when crushed. In the fall the tree produces a small cone-shaped fruit containing tiny nutlets.
The existing wild trees might be the last survivors of what was once a more widespread species. But they could also be early specimens of a newly-evolved species which hasn't yet had time to expand into a larger area. The wild trees are located near some Sweet Birches (Betula lenta), and the two species appear to be closely-related. It's possible that the roundleaf birch is a recent evolutionary split-off.
Because this species is so new to cultivation, there are uncertainties about its cold-hardiness and environmental preferences. But it would likely do best in conditions similar to those preferred by other native birches, particularly the Sweet Birch.
Scientific Name: Betula uber
Common Names: Virginia Roundleaf Birch, Roundleaf Birch, Ashe Birch
Plant Type: Small to mid-size tree
Height: 20 - 40 feet
Cultivation Zones: Uncertain. Possibly 5 - 7. (Wild trees are in the southern part of Zone 6. Other native birches are hardy northward at least through Zone 5.)
Native Range: This species has been found naturally at only one locality, a small area in southwestern Virginia. The approximate location is marked by a single dot on the following map.
Map Source: U.S. Forest Service. (See General Note C)
Cultivation: The needs of this plant are probably similar to those of other native birches. Put it in a mostly sunny location, and give it moist well-drained soil. A mulch can help hold in moisture. Note that most birches don't do well in hot climates. Go to Cultivation for more information.
Plant Sources: Because of its rarity, Roundleaf Birch can be difficult to obtain, but efforts are being made to make it available. Possible commercial sources include Shooting Star Nursery and Forest Farm. For links to these suppliers, go to Sources of Plants.
More information about the discovery and rescue of this species can be found in this article.