A birch is a thin-leaved deciduous hardwood tree of the genus Betula, in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. They are typically short-lived pioneer species and are widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates. Birch wood is used for a wide range of purposes.
Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams, numbering a total of 167 species. They are mostly natives of the temperate Northern Hemisphere, with a few species reaching the Southern Hemisphere in the Andes in South America. Their typical flowers are catkins and often appear before leaves.
Alnus glutinosa, the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.
Betula pendula, commonly known as silver birch, warty birch, European white birch, or East Asian white birch, is a species of tree in the family Betulaceae, native to Europe and parts of Asia, though in southern Europe, it is only found at higher altitudes. Its range extends into Siberia, China, and southwest Asia in the mountains of northern Turkey, the Caucasus, and northern Iran. It has been introduced into North America, where it is known as the European white birch or weeping birch and is considered invasive in some states in the United States and parts of Canada. The tree can also be found in more temperate regions of Australia.
Betula pubescens, commonly known as downy birch and also as moor birch, white birch, European white birch or hairy birch, is a species of deciduous tree, native and abundant throughout northern Europe and northern Asia, growing further north than any other broadleaf tree. It is closely related to, and often confused with, the silver birch, but grows in wetter places with heavier soils and poorer drainage; smaller trees can also be confused with the dwarf birch.
Betula nigra, the black birch, river birch or water birch, is a species of birch native to the Eastern United States from New Hampshire west to southern Minnesota, and south to northern Florida and west to Texas. It is one of the few heat-tolerant birches in a family of mostly cold-weather trees which do not thrive in USDA Zone 6 and up. B. nigra commonly occurs in floodplains and swamps.
Betula papyrifera is a short-lived species of birch native to northern North America. Paper birch is named after the tree's thin white bark, which often peels in paper-like layers from the trunk. Paper birch is often one of the first species to colonize a burned area within the northern latitudes, and is an important species for moose browsing. Primary commercial uses for paper birch wood are as boltwood and sawlogs, while secondary products include firewood and pulpwood. It is the provincial tree of Saskatchewan and the state tree of New Hampshire.
Betula alleghaniensis, the yellow birch, golden birch, or swamp birch, is a large tree and an important lumber species of birch native to northeastern North America. Its vernacular names refer to the golden color of the tree's bark. In the past its scientific name was Betula lutea, the yellow birch.
Betula lenta is a species of birch native to eastern North America.
Betula nana, the dwarf birch, is a species of birch in the family Betulaceae, found mainly in the tundra of the Arctic region.
Betula glandulosa, the American dwarf birch, also known as resin birch or shrub birch, is a species of birch native to North America.
Betula halophila is a species of plant in the Betulaceae family. It is endemic to China.
Betula ermanii, or Erman's birch, is a species of birch tree belonging to the family Betulaceae. It is an extremely variable species and can be found in Northeast China, Korea, Japan, and Russian Far East. It can grow to 20 metres (66 ft) tall. It is noted for its peeling bark, which can sometimes be removed in sheets, but usually shreds and hangs from the trunk and under branches. Yellow-brown male catkins appear with the leaves in spring.
Betula utilis, the Himalayan birch, is a deciduous tree native to the Western Himalayas, growing at elevations up to 4,500 m (14,800 ft). The Latin specific epithet utilis means "useful", and refers to the many uses of the different parts of the tree. The white, paper-like bark was used in ancient times as a writing surface for manuscripts of Sanskrit literature. It is still used as paper for the writing of mantras, with the bark placed in an amulet and worn for protection. Selected varieties are used for landscaping throughout the world, even while some areas of its native habitat are being lost due to overuse of the tree for firewood.
Betula albosinensis, commonly known as the Chinese red birch, is a species of birch in the family Betulaceae, native to Western China. It is notable for its distinctive peeling bark and is cultivated as an ornamental tree.
Betula alnoides is a species of birch that is native to countries including Bangladesh, Bhutan, Cambodia, China, India, Laos, Myanmar, Nepal, Thailand and Vietnam, at elevations of 300–2,100 m (1,000–7,000 ft) and higher in some cases. It is the southernmost of all known species of the genus Birch, whose natural range reaches approximately 12° N in Cardamom Mountains, Cambodia.
Betula chichibuensis, commonly known as Chichibu birch, is a species of birch native exclusively to limestone outcrops in the Okuchichibu and Kitakami Mountains of central and northeast Honshu, Japan. The tree is rated as Critically Endangered on the IUCN Red List due to its extreme rarity and limited range.
Betula schmidtii, the iron birch or Schmidt's birch, is a species of flowering plant in the family Betulaceae. It is native to Manchuria, Korea, Primorsky Krai of the Russian Far East, and Japan. A tree reaching 30 m (100 ft) with nearly black bark, its wood is so dense that it does not float, and is used where a tough, durable material is desired.
Betula celtiberica, the Iberian white birch, is a species of flowering plant in the family Betulaceae, native to Great Britain and northwestern Spain. In Spain is it often found on north-facing valley slopes, forming mixed mesic forests with the common beech Fagus sylvatica.
