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.
Cyclocarya female catkins 25–30 cm long at maturity, bearing several small winged nuts with a circular wing 2.5–6 cm diameter right round the nut (instead of two wings at the sides as in "Pterocarya"). Cyclocarya Cyclocarya is a genus of flowering plants in the family Juglandaceae, comprising a single species Cyclocarya paliurus (qing qian liu or wheel wingnut), formerly treated in the genus "Pterocarya" as "Pterocarya paliurus". It is native to eastern and central China. It is a deciduous tree growing to 30 m tall. The foliage is similar to "Pterocarya", with pinnate leaves 20–25 cm long with five to eleven