Betula uber Betula uber Betula uber, Virginia round-leaf birch, is a rare species of tree in the birch family. One of the most endangered species of North American trees, it is endemic to Smyth County, in the U.S. state of Virginia. It is part of the temperate broadleaf and mixed forests biome. The tree was first described in 1918 as a variety of "Betula lenta", and elevated to species status in 1945. It hybridizes with "B. lenta" and it has been suggested that it is actually a round-leaved mutant form of "B. lenta". Some authorities prefer to treat it as a variety.
Crataegus Crataegus Crataegus (), commonly called hawthorn, quickthorn, thornapple, May-tree, whitethorn, or hawberry, is a large genus of shrubs and trees in the family Rosaceae, native to temperate regions of the Northern Hemisphere in Europe, Asia and North America. The name "hawthorn" was originally applied to the species native to northern Europe, especially the common hawthorn "C. monogyna", and the unmodified name is often so used in Britain and Ireland. The name is now also applied to the entire genus and to the related Asian genus "Rhaphiolepis". The Latin name "Crataegus" is from the Greek "kratos" "strength" and "akis" "sharp", referring