Birch

Birch refers to trees and shrubs of the genus Betula in the family Betulaceae. The genus contains about 30 to 60 species, native to the temperate and boreal regions of Europe, Asia, and North America, with some species extending into montane tropical regions. Birches are typically deciduous, with slender trunks and often distinctive bark that peels in thin, papery layers. Leaves are simple, ovate or lanceolate with serrated margins, and are arranged alternately. In spring, birches produce catkins; male catkins are yellow-green and glandular, while female catkins develop into small-winged seeds that disperse by wind.

Ecology and habitat: Birches prefer moist, well-drained soils but tolerate a range of conditions. They are often among the first trees to colonize disturbed sites, acting as pioneer species in boreal and temperate forests. They form limited mycorrhizal associations and are valued for their rapid growth. The bark contains compounds such as betulin and betulinic acid, and the wood is light and relatively soft.

Uses: Birch wood is used for furniture, cabinetry, plywood, turning, and veneer; paper birch is a source of pulp. The bark has been used by various cultures for waterproof containers, canoes, and religious or decorative objects. Sap can be collected in spring and processed into beverages or, in some regions, into birch syrup. The trees also have ornamental value in parks and streets.

Notable species: Betula pendula (silver birch) is widespread in Europe; Betula pubescens (downy birch) occurs across northern Europe and Asia; Betula papyrifera (paper birch) is common in North America; Betula lenta (sweet birch) is native to eastern North America; Betula utilis inhabits the Himalayas.