Genus Betula
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae.Species in the genus Betula of plants
Betula oycoviensis - B. oycoviensis is a genetic cross of two other species of Betula; B. pendula and B. szaferi, the latter having specimens in a botanic garden, and evidently nowhere else. Rafaël Govaerts, a botanist at Kew Gardens, treats it as a variety of Betula pendula .
Betula raddeana - Betula raddeana is a species of plant in the Betulaceae family. It is found in Georgia and Russia. It is threatened by habitat loss.
Betula szaferi - Betula szaferi was a species of plant in the Betulaceae family. It was endemic to Poland.
Virginia round-leaf birch - The tree was first described in 1918 as a variety of Betula lenta, and elevated to species status in 1945.