text: betula pendula betula pendula , commonly known as silver birch or warty 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 , and is considered invasive in some states in usa and in parts of canada . the tree can also be found in more temperate regions of australia . the silver birch is a medium - sized deciduous tree that owes its common name to the white peeling bark on the trunk . the twigs are slender and often pendulous and the leaves are roughly triangular with doubly serrate margins and turn yellow in autumn before they fall . the flowers are catkins and the light , winged seed get widely scattered by the wind . the silver birch is a hardy tree , a pioneer species , and one of the first trees to appear on bare or fire - swept land . many species of birds and animals are found in birch woodland , the tree supports a wide range of insects and the light shade it casts allows shrubby and other plants to grow beneath its canopy . it is planted decoratively in parks and gardens and is used for forest products such as joinery timber , firewood , tanning , racecourse jumps and brooms . various parts of the tree are used in traditional medicine and the bark contains triterpenes which have been shown to have medicinal properties . description the silver birch is a medium - sized deciduous tree , typically reaching 15 to 25 m ( 49 to 82 ft ) tall ( exceptionally up to 31 metres ( 102 ft ) ) , with a slender trunk usually under 40 cm ( 16 in ) diameter . the bark on the trunk and branches is golden - brown at first , but later this turns to white as a result of papery tissue developing on the surface and peeling off in flakes . the bark remains smooth until the tree gets quite large , but in older trees , the bark thickens , becoming irregular , dark and rugged . young branches have whitish resin warts and the twigs are slender , hairless and often pendulous . the buds are small and sticky , and development is , that is to say the terminal bud dies away and growth continues from a lateral bud . some shoots are long and bear the male catkins at the tip , while others are short and bear female catkins . the immature male catkins are present during the winter but the female catkins develop in the spring , soon after the leaves unfurl . the leaves have short slender stalks and are 3 to 7 cm ( 1 . 2 to 2 . 8 in ) long , triangular with broad , untoothed , wedge - shaped bases , slender pointed tips and coarsely double - toothed , serrated margins . they are sticky with resin at first but this dries as they age leaving small white scales . the foliage is a pale to medium green and turns yellow early in the autumn before the leaves fall . in mid - summer , the female catkins mature and the male catkins expand and release pollen , and wind pollination takes place . the small 1 to 2 mm winged seeds ripen in late summer on pendulous , cylindrical catkins 2 to 4 cm ( 0 . 8 to 1 . 6 in ) long and 7 mm ( 0 . 3 in ) broad . the seeds are very numerous and are separated by scales , and when ripe , the whole catkin disintegrates and the seeds are spread widely by the wind . distribution and habitat the silver birch grows naturally from western europe eastwards to kazakhstan , the sakha republic in siberia , mongolia and the xinjiang province in china , and southwards to the mountains of the caucasus and northern iran , iraq and turkey . it is also native to northern morocco and has become naturalised in some other parts of the world . in the southern parts of its range it is mainly found in mountainous regions . its light seeds are easily blown by the wind and it is a pioneer species , one of the first trees to sprout on bare land or after a forest fire . it needs plenty of light and does best on dry , acid soils and is found on heathland , mountainsides and clinging to crags . its tolerance to pollution make it suitable for planting in industrial areas and exposed sites . it has been introduced into north america where it is known as the european white birch , and is considered invasive in the states of kentucky , maryland , washington and wisconsin . it is naturalised and locally invasive in parts of canada . taxonomy the closely related betula in northern asia and betula of central asia are also treated as varieties of silver birch by some botanists , as b. pendula var. and b. pendula var. respectively ( see birch classification ) . b. pendula is distinguished from the related downy birch ( b. pubescens , the other common european birch ) in having hairless , warty shoots ( hairy and without warts in downy birch ) , more triangular leaves with double serration on the margins ( more ovoid and with single serrations in downy birch ) , and whiter bark often with scattered black fissures ( greyer , less fissured , in downy birch ) . it is also distinguished , silver birch being diploid ( with two sets of chromosomes ) , whereas downy birch is tetraploid ( four sets of chromosomes ) . hybrids between the two are known , but are very rare , and being triploid , are sterile . the two have differences in habitat requirements , with silver birch found mainly on dry , sandy soils , and downy birch more common on wet , poorly drained sites such as clay soils and peat bogs . silver birch also demands slightly more summer warmth than does downy birch , which is significant in the cooler parts of europe . many north american texts treat the two species as conspecific ( and cause confusion by combining the downy birch 's alternative vernacular name ' white birch ' , with the scientific name b. pendula of the other species ) , but they are regarded as distinct species throughout europe . synonyms include betula pendula var. ( . ) - ahti , b. pendula var. ( . ) . , b. pendula var. lapponica ( . ) - ahti , b. raf . , b. montana , b. , b. verrucosa . , b. verrucosa var. lapponica . , and b. . the rejected name betula alba l. also applied in part to b. pendula , though also to b. pubescens . ecology the silver birch has an open canopy which allows plenty of light to reach the ground . this allows a variety of mosses , grasses and flowering plants to grow beneath which in turn attract insects . flowering plants often found in birch woods include primrose ( primula vulgaris ) , violet ( viola ) , bluebell ( hyacinthoides non - scripta ) , wood anemone ( anemone ) and wood sorrel ( ) . small shrubs that grow on the forest floor include ( vaccinium ) and ( vaccinium vitis - ) . birds found in birch woodland include the chaffinch , tree pipit , willow warbler , nightingale , robin , woodcock , redpoll and green woodpecker . the branches of the silver birch often have tangled masses of twigs known as witch 's brooms growing among them , caused by the fungus taphrina . old trees are often killed by the decay fungus and fallen branches rot rapidly on the forest floor . this tree commonly grows with the mycorrhizal fungus amanita muscaria in a mutualistic relationship . this applies particularly to acidic or nutrient - poor soils . other mycorrhizal associates include leccinum scabrum and cantharellus cibarius . it has been shown that , as well as mycorrhiza , the presence of microfauna in the soil assists the growth of the tree , as it enhances the mobilization of nutrients . the larvae of a large number of species of butterflies , moths and other insects feed on the leaves and other parts of the silver birch . in germany , almost 500 species of insect have been found on silver and downy birch including 106 beetles and 105 lepidopterans , with 133 insect species feeding almost exclusively on birch . birch dieback disease can affect planted trees , while naturally regenerated trees seem less susceptible . this disease also affects betula pubescens and in 2000 was reported at many of the sites planted with birch in scotland during the 1990s . in the united states , the wood is attacked by the bronze birch borer ( ) , an insect pest to which it has no natural resistance . uses silver birch is often planted in parks and gardens , grown for its white bark and gracefully drooping shoots , sometimes even in warmer - than - optimum places such as los angeles and sydney . in scandinavia and other regions of northern europe , it is grown for forest products such as lumber and pulp , as well as for aesthetic purposes and ecosystem services . it is sometimes used as a pioneer and nurse tree elsewhere . silver birch wood is pale in colour with no distinct heartwood and is used in making furniture , plywood , veneers , parquet blocks , skis , kitchen utensils and in turnery . it makes a good firewood that produces a good heat when burnt but is quickly consumed by the flames . of bark are used for making roof shingles and wooden footwear . historically , the bark was used for tanning . bark can be heated and the resin collected ; the resin is an excellent waterproof glue and useful for starting fires . the thin sheets of bark that peel off young wood contain a waxy resin and are easy to ignite even when wet . the dead twigs are also useful as kindling for outdoor fires . birch brushwood is used for racecourse jumps and brooms . in the spring , large quantities of sap rise up the trunk and this can be tapped . it contains around 1 % sugars and can be used in a similar way to maple syrup , being drunk fresh , concentrated by evaporation or fermented into a " wine " . in sweden , the bark of birch trees was ground up and used to make bark bread , a form of famine food . the removal of bark was at one time so widespread that carl linnaeus expressed his concern for the survival of the woodlands . silver birch is used in traditional medicine as a diuretic and is reputed to be useful in the treatment of high blood pressure , high cholesterol , obesity , gout , kidney stones , nephritis , cystitis , digestive disturbances and respiratory diseases . for these purposes , a decoction of the bark or leaves is generally used . externally silver birch is used to promote healing , relieve pain and treat inflammations and infections of the skin such as eczema and psoriasis . the outer part of the bark contains up to 20 % . the main components in the essential oil of the buds are α - copaene ( ~ 10 % ) , germacrene d ( ~ 15 % ) and δ - cadinene ( ~ 13 % ) . also present in the bark are other substances which have been shown to have anti - inflammatory , antiviral and anti - cancer properties . the silver birch is finland 's national tree . leafy , fragrant boughs of silver birch ( called or ) are used to gently beat oneself in the finnish sauna culture . cultivation successful birch cultivation requires a climate cool enough for at least the occasional winter snowfall . as they are shallow - rooted , they may require water during dry periods . they grow best in full sun planted in deep , well - drained soil . cultivars ' is called " curly birch " in finland ; the wood is hard and decorative and is used in wood - carving . ' agm ( commonly misidentified as ' ' ) has deeply incised leaves and weeping branches . ' has dark purple leaves . ' agm has an erect trunk with weeping branchlets . ' has dense , weeping growth with no central leader and requires being grafted onto a standard stem of normal silver birch . the cultivars marked agm above have gained the royal horticultural society 's award of garden merit .