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.
Fokienia Tuyên Quang, Yên Bái and Vĩnh Phú), west central Vietnam (provinces of Đắk Lắk, Gia Lai, Lâm Đồng), and west to northern Laos. The name derives from the old Romanised name of Fujian province, China, from where the first specimen was introduced to Europe, collected by Captain Hodgins in 1908. "Fokienia" is an evergreen tree, 25–30 m tall. It has greyish-brownish bark that peels off when the tree is young. On older trees, the bark presents longitudinal fissures and becomes aromatic. The leaves are arranged in flattened branchlet systems, with the branchlets in one plane. The leaves on adult trees