Description
A hardy, deciduous tree of the family Betulaceae that is common to North America, Europe and Asia. Birch tress are readily distinguished by their white bark and diamond-shaped leaves. The lightweight bark is full of natural waxes, oils and tannins that make it tough, durable, and waterproof. Thin sheets of bark were commonly used for paper in Central Asia and the Far East. The water-impervious bark was used for wigwams, canoes, and shoes for North American Indians. Birch produces a strong, pale yellow-brown wood with a close, straight grain and uniform texture that finishes to a smooth surface. It is sometimes dyed to imitate mahogany. Birch is used for tools handles, plywood, hoops, shoe heels, flooring, furniture, cabinetry, and firewood. Dyes can also be obtained from various parts of birch trees. The leaves, usually gathered before they develop a mature green color, produce a yellow dye. The bark produces a pale brown color. The female catkins (a long shoot bearing flowers with no leaves) are boiled to produce a dull yellow color. Birch bark oil and birch beer are made from sap obtained from the trees. The sap allows birch bark to burn even when it is wet.
For micrographs of thin sections, also see paper birch, yellow birch, and black birch.
Synonyms and Related Terms
betula; birk (Dan.); bouleau (Fr.); Birke (Deut.); beulla (It.); abedul (Esp.); berk (Ned.); betula (Port.); bjørk (Nor.); brzoza (Pol.); björk (Sven.); black birch (Betula nigra); paper birch (Betula papyrifera); cherry birch (Betula lenta); yellow birch (Betula lutea); white birch (Betula pendula); sweet birch (Betula lenta); river birch (Betula nigra)
| specific gravity = 0.67 |
| 32-48 ppcf |
Other Properties
Tree height = 20-25m Bark = light gray to white, often peeling in papery strips
Wood is moderately acidic. Color: light yellow-brown to reddish brown. Rings: obscure. Pores: diffuse, fine. Grain: faint. Rays: obscure. On quarter sawed wood, rays appear as small brown flakes. Hard, heavy, poor weatherability.
Additional Information
° Schoch, W., Heller, I., Schweingruber, F.H., Kienast, F., 2004:
Wood anatomy of central European Species: Common Birch, White Birch,
Betula alba (B. pendula / B. pubescens)
|
Last updated on: 10/30/2007 7:57:43 AM
|
|
 |
|
