Betula lenta L. var. uber Ashe

Locations ofBetula lenta L. var. uber Ashe in Virginia

Show image with county labels


Botanical Name
Betula lenta L. var. uber Ashe
Common Name
Virginia Roundleaf Birch
Betula uber (Ashe) Fern.
Flora of Virginia Name/Status
Betula lenta L. var. uber Ashe
Originally found by W.W. Ashe in 1914 and subsequently "lost" for 60 years until rediscovered by Douglas Ogle in 1975. The story of botanical intrigue is told in The New Yorker 51:58-69 (1976). Subsequent research demonstrated that the round leaves are inherited in a strict Mendelian ratio, being expressed only when the "round-leaved gene" is present on both chromosomes, i.e., a double recessive character trait. This prompted Cronquist to demote Betula uber to a forma under Betula lenta. This interpretation, however, does not account for the smaller stature and more "twiggy" appearance of the trees. The recovery plan for this endangered species has established additional populations in the region where many individuals carry the "round-leaved gene" in single copy, thus phenotypically looking like Betula lenta in leaf form.
Young mixed hardwood forest in a small mountain-valley floodplain with stoney alluvial soils. The only known site in the world is in Smyth County (Ridge and Valley province).
Native Status

To save this map, right-click (control-click for Mac users) on the map and choose "Save Image As...".