A deciduous tree of the genus Betula which is distributed over much of North America, in Asia south to the Himalaya, and in Europe. About 40 species are known. The birches comprise the family Betulaceae in the order Fagales. The sweet birch, B. lenta (illus. a), the yellow birch, B. alleghaniensis (illus.b), and the paper birch, B. papyrifera, are all important timber trees of the eastern United States. The yellow and the paper species extend into Canada. The gray birch, B. populifolia, is a smaller tree of the extreme northeastern United States and adjacent Canada. Both sweet (black) and yellow birches can be recognized by the wintergreen taste of the bark of the young twigs. A flavoring similar to oil of wintergreen is obtained from the bark of the sweet birch. The paper and gray birches can be easily identified by their white bark. The bark of the paper birch peels off in thin papery sheets, a characteristic not true of the gray birch. The river birch, B. nigra, is a less common tree of wet soils and banks of streams and is important as an ornamental and for erosion control. The hard, strong wood of the yellow and the sweet birches is used for furniture, boxes, baskets, crates, and woodenware. The European birches, B. pubescens and B. pendula, are the counterparts of the paper and gray birches in the United States. European birches are also cultivated in America.