birch(redirected from Betula species)
Also found in: Dictionary, Thesaurus, Medical, Legal.
birch,common name for some members of the Betulaceae, a family of deciduous trees or shrubs bearing male and female flowers on separate plants, widely distributed in the Northern Hemisphere. They are valued for their hardwood lumber and edible fruits and as ornamental trees. The species of Betulaceae native to the United States represent five genera—Alnus (alderalder
, name for deciduous trees and shrubs of the genus Alnus of the family Betulaceae (birch family), widely distributed, especially in mountainous and moist areas of the north temperate zone and in the Andes. The black alder (A.
..... Click the link for more information. ), Betula (the birches), Corylus (hazelhazel,
any plant of the genus Corylus of the family Betulaceae (birch family), shrubs or small trees with foliage similar to the related alders. They are often cultivated for ornament and for the edible nuts.
..... Click the link for more information. ), and Carpinus (hornbeamhornbeam
name in North America for two groups of trees of the family Betulaceae (birch family), native to the eastern half of the continent. Carpinus caroliniana, also called blue beech and water beech, has smooth gray bark.
..... Click the link for more information. ) and Ostrya (hop hornbeam), both also called ironwood. The sixth genus, Ostryopsis, is restricted to Mongolia. The birches, beautiful bushes or trees of temperate and arctic regions, are often found mingled with evergreens in northern coniferous forests. Most American species are trees of the Northeast; a few smaller and scrub species grow in the West. The close-grained hardwood of several of the trees is valued for furniture, flooring, and similar uses (in America, particularly that of the yellow birch, B. lutea); stained birch provides much of the so-called mahogany of lower-priced furniture. White-barked birches are often used as ornamental trees, e.g., the famous paper, or canoe, birch (B. papyrifera) of the N United States and Canada. Its bark, which separates in layers, was used by the Native Americans for canoes and baskets. Various birches have yielded sugar, vinegar, a tea from the leaves, and a birch beer from the sap. The sweet, or black, birch (B. lenta) is now the chief source of oil of wintergreenwintergreen
low evergreen plant (Gaultheria procumbens) of the family Ericaceae (heath family), native to sandy and acid woods (usually of evergreens) of E North America and frequently cultivated.
..... Click the link for more information. . The Betulaceae is classified in the division MagnoliophytaMagnoliophyta
, division of the plant kingdom consisting of those organisms commonly called the flowering plants, or angiosperms. The angiosperms have leaves, stems, and roots, and vascular, or conducting, tissue (xylem and phloem).
..... Click the link for more information. , class Magnoliopsida, order Fagales.
(genus Betula), deciduous monoecious trees and shrubs of the Betulaceae family. The bark of the trunk ranges in color from white to black. The leaves are sequential, simple, and petiolate. The staminate flowers, with two bifurcated stamens, are gathered in hanging catkins, which in summer are formed at the ends of annual shoots. Pistillate flowers without perianths, usually in threes (in dichasia) in axils of bracteal husks, are gathered in single catkins, which are displayed in the spring of the year, when they blossom in axils of young leaflets. The birch tree blooms in early spring, almost simultaneously with the opening of the leaves. The fruit is one-seeded, nutlike, flat, and two-winged. Seeds ripen in the summer or fall. The birch tree generally grows rapidly, particularly when it is young. It readily populates areas in which other vegetation does not exist and is often a pioneer species.
There are about 100 (more, by some data) polymorphous species growing in the temperate and cool regions of the northern hemisphere and the mountains of the subtropics; there are about 50 species in the USSR. Many birches are economically important—the valuable lumber-forming and decorative species, particularly the European white birch (Betula pendula or B. verrucosa), the Old World white birch (B. pubescens), the flat-leaf birch (B. platyphylla), the ribbed, or yellow, birch (B. costata), and the Schmidt, or iron, birch (B. Schmidtii). Most species of birch require light, are quite drought- and frost-resistant, and grow in many types of soil. The lumber and bark of many birch species are used in various sectors of the economy. The buds and leaves of the European white birch and Old World white birch are used for medicinal purposes. The buds, which contain 3.5–6 percent essential oil, are sometimes used in infusions as a diuretic and externally as a massage for aches in joints. The most prevalent species of birch is the European white birch. Trees reach 25 m in height and 80 cm in diameter. Birches tolerate a certain amount of salinization of the soil and aridity of the air; they live to 150 years and more. They are observed to 65° N lat. in Western Europe; in the USSR, they are found throughout nearly the entire forest and forest-steppe zone of the European part, western Siberia, Transbaikal, Saiany, Altai, and the Caucasus. Birches grow in combination with coniferous and deciduous varieties. In some places they form vast birch forests; and in the forest-steppe zone of the Trans-Volga Region and western Siberia, they form the so-called birch groves, which alternate with fields and steppe areas. Birches are used as field-protecting strips and as decoration. The lumber is prized for furniture production; it is used for veneer and various articles.
REFERENCEDerev’ia i kustarniki SSSR, vol. 2. Moscow-Leningrad, 1951.
A. P. SHIMANIUK