VIRGINIA ROUND-LEAVED BIRCH: Betula uber

Virginia is uniquely positioned to accommodate a great diversity of flowering plants. Its latitude, topography, and climate allow plants primarily adapted to northern climates as well as those adapted to southern climes to grow within its borders. Virtually all plants native to Virginia can be found growing in other states (plants tend not to respect political boundaries).

But, Virginia lays claim to one plant that is found only within its borders: the Virginia round-leaved birch, Betula uber. This plant’s relatively recent rediscovery in 1975 and its inclusion on the Federal List of Endangered Species make it of particular interest and worthy of selection as a true Virginia Native.

The Virginia round-leaved birch is also known as Virginia birch, or Ashe’s birch in recognition of William Willard Ashe, a forester who first described this species. It is a member of the birch family, Betulaceae, which includes six genera, five of which are native to North America. Familiar members of this family include hop hornbeams, ironwoods, alders, birches, and hazelnuts in the genera Ostrya, Carpinus, Alnus, Betula, and Corylus respectively. Members of several of these genera are of interest for their usefulness-hazelnuts for food, wood of birches for furniture and boat building, and species of ironwood and birches for plantings.

The genus Betula consists of 50 species of trees and shrubs that are distributed throughout temperate and sub-arctic regions of the northern hemisphere. Eight of 15 North American species grow in a variety of environments from sea level to about 4000 feet elevation in the southern Appalachians. Birches tend to prefer well-drained soils in cool areas, particularly along lakes and streams.

in one locality in Smyth County in southwest Virginia. It grows as a small tree to about 25 to 30 feet in height. The plant, like cherry and yellow birch, produces a characteristic wintergreen odor when its shoots or leaves are crushed. The bark is typical of birches, being dark and covered with lenticels which are openings that allow for gas exchange.

The plant’s leaves are among its most distinctive traits, measuring about 1-inch in length with an almost rounded tip and base. Leaves are smooth over the blade, coarsely toothed along the margins, and attached to stems in the alternating pattern typical of other birches.

The tiny, clustered flowers form structures called catkins. Male and female flowers are located on separate distinctive catkins within an an individual plant. Male catkins, each measuring 2.5 to 3 inches, appear in groups. Female catkins produce erect fruits that measure 1 to 1.5 inches in length.

At present, no ornamental use can be recommended for this plant because trade in endangered species is restricted.

The tale of the rediscovery of the Virginia round-leafed birch reads like a scientific detective story. The plant had been documented on herbarium sheets prepared by Ashe in 1914 and sent to major herbariums. Ashe described the plant he’d found as a variety of the sweet birch, Betula lenta.

In the 1940’s, Dr. Merritt Lyndon Fernald, a prominent botanist at Harvard, studied the American birches. After examining the herbarium specimens prepared by Ashe, he elevated the plant to the level of species and named it Betula uber. But, in a subsequent attempt to study the species in 1953, a student named Albert G. Johnson (and later, others) failed to find it in the wild.

In the 1960s, Peter Mazzeo, a researcher (and eventually herbarium curator) at the U.S. National Arboretum became interested in the lost Ashe’s birch and began a detailed study of all materials he could gather related to the plant. In Mazzeo’s painstaking research he rediscovered an overlooked set of herbarium specimens of Betula uber. The critical clue they held was the collection locality typically noted, but in more or less detail depending on the collector. Mazzeo found reference to two streams, not one, along which the plant had been collected

In the meantime, Mazzeo’s writings about Betula uber sparked the interest of Douglas Ogle, a biology instructor at Virginia Highlands Community College. On his summer vacation, Ogle began to methodically search for the plant in nature along the creeks in Smyth

On August 22, 1975, Ogle discovered and marked a group of plants he was confident were Betula uber. A call to Mazzeo resulted in arrangements for a trip, and these two, joined by a small contingent of interested colleagues, verified Ogle’s discovery of about 12 mature individuals and a few seedlings.

Following so closely after the 1973 passage of the Federal Endangered Species Act, this discovery attracted national attention. It was the first woody plant to be federally listed as endangered Much concern for the species’ persistence in the early years has been relieved by the successful establishment of seedlings in its native environment following fencing off the small number of mature trees, with the cooperation of private landholders.

Other measures to preserve the species included captive propagation by foresters at Virginia Tech, who distributed seedlings in groups of three to interested botanic gardens and arboretums.

The Orland E. White Arboretum now exhibits its three individuals of Virginia round-leafed birch in the birch family collection east of Lake Georgette.-Chris Sacchi

Editors Note: For a ful1 account of the search for Betula uber, see “Our Footloose Correspondents,” The New Yorker, January 12, 1976- p. 58-69.

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