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BirchMany species;
see text and classification Birch is the name of any tree of the genus Betula, in the family Betulaceae, closely related to the beech/oak family, Fagaceae. These are generally small to medium-size trees or shrubs, mostly of northern temperate climates. The simple leaves may be toothed or lobed. The fruit is a small samara, although the wings may be obscure in some species. They differ from the alders (Alnus, the other genus in the family) in that the female catkins are not woody and disintegrate at maturity, falling apart to release the seeds, unlike the woody cone-like female alder catkins. Birch is a food plant for a number of species of Lepidoptera including Oak Hook-tip, Large Emerald, Common Emerald, Common Marbled Carpet, November Moth and Autumnal Moth. Species - Birches of North America include:
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- Birches of Europe and Asia include:
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- Note: many American texts have B. pendula and B. pubescens confused, though they are distinct species with different chromosome numbers
Uses Birches are versatile trees, used for many purposes. The sap, bark, leaves, wood, twigs, and roots are used for food, construction materials, medicinal treatments, lubricants, and other practical applications. Extracts of birch are used for flavoring or leather oil, and in cosmetics such as soap or shampoo. In the past, commercial oil of wintergreen (methyl salicylate) was made from the Sweet Birch (Betula lenta). Birch tar, extracted from birch bark, was used as a lubricant and for medicinal purposes. Birch leaves are used to make a diuretic tea and to make extracts for dyes and other purposes. Birch sap is drunk as a tonic or rendered into birch syrup, vinegar, beer, soft drinks, and other foods. Many of the First Nations of North America prized the birch for its bark, which due to its light weight, flexibility, and the ease with which it could be stripped from trees, was often used for the construction of strong, waterproof but light-weight canoes. The bark is high in betulin and betulinic acid, phytochemicals which have potential as pharmaceuticals, and other chemicals which show promise as industrial lubricants. See also External links
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