Betula lenta L. var. uber Ashe

Locations ofBetula lenta L. var. uber Ashe in Virginia

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Detail

Family
Betulaceae
Botanical Name
Betula lenta L. var. uber Ashe
Common Name
Virginia Roundleaf Birch
Synonym(s)
Betula uber (Ashe) Fern.
Flora of Virginia Name/Status
Betula lenta L. var. uber Ashe
Comments
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.
Habitat
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
Native

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