Botanical Name: Betula papyrifera
Species: B. papyrifera
Synonyms: Betula alba var. papyrifera, Betula lenta var. papyrifera
Common Names: Paper Birch, Mountain paper birch, Kenai birch, white birch and canoe birch
Habitat: Betula papyrifera is native to Northern N. America to Greenland. It grows in woods, usually on slopes, edges of ponds, streams and swamps etc. Found in a wide range of soil conditions, but the best specimens are found in well-drained sandy-loam soils.
Betula papyrifera is a medium-sized deciduous tree typically reaching 20 metres (66 ft) tall, and exceptionally to 130 feet (40 m) with a trunk up to 30 inches (0.76 m) diameter. Within forests it is often grows with a single trunk but when grown as a landscape tree it may develop multiple trunks or branch close to the ground.
Paper birch is a typically short lived species. It handles heat and humidity poorly and may only live 30 years in zones six and up, while trees in colder-climate regions can grow over 100 years. B. papyrifera will grow on many soil types, from steep rocky outcrops to flat muskegs of the boreal forest. Best growth occurs on deeper, well drained to dry soils depending on the location.
In older trees the bark is white, commonly brightly so, flaking in fine horizontal strips to reveal a pinkish or salmon colored inner bark. It is often with small black marks and scars. In individuals younger than five years, the bark appears a brown red color with white lenticels, making the tree much harder to distinguish from other birches. The bark is highly weather-resistant. The bark has a high oil content and this gives it its waterproof and weather resistant characteristics. Often, the wood of a downed paper birch will rot away leaving the hollow bark intact.
* The leaves are dark green and smooth on the upper surface, the lower surface is often pubescent on the veins. The leaves are alternately arranged on the stem, oval to triangular in shape, 5–10 cm (2–4 in) long and about 2/3 as wide. The leaf is rounded at the base and tapering to an acutely pointed tip. The leaves have a doubly serrate margin with relatively sharp teeth. Each leaf has a petiole ~2.5 cm (1 in) long which connects it to the stems.
* The fall color is a bright yellow color which contributes to the bright colors within the northern deciduous forest.
* The leaf buds are conical and small and green-colored with brown edges.
* The stems are a reddish brown color and may be somewhat hairy when young.
* The flowers are wind-pollinated catkins, the female flowers are greenish and 1.5 inches (3.8 cm) long growing from the tips of twigs. The male (staminate) flowers are 2–4 inches (5.1–10.2 cm) long and a brownish color. It flowers from mid-April to June depending on location.Paper birch is monoicous meaning that one plant has both male and female flowers.
* The fruit matures in the fall. The mature fruit is composed of numerous tiny winged seeds packed between the catkin bracts. They drop between September and spring. At 15 years of age the tree will start producing seeds but will be in peak seed production between 40–70 years. The seed production is irregular with a heavy seed crops being produced typically every other year and with at least some seeds being produced every year. In average seed years, 1 million seeds/acre are produced but in bumper years 35 million/acre may be produced. The seeds are light and blow in the wind to new areas, they may also blow along the surface of the snow.
* The roots are generally shallow and occupy the upper 24 inches (61 cm) of the soil and do not form taproots. High winds are more likely to break the trunk than to uproot the tree.
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Succeeds in a well-drained loamy soil in a sunny position. Tolerates most soils including poor soils and heavy clays. Fairly wind tolerant. This species is very unhappy on our windy site in Cornwall. A fast-growing but short-lived species. It is often a pioneer species of areas ravaged by fire. The trunk and branches are easily killed by fire, though the tree usually regenerates from the roots. It hybridizes freely with other members of this genus. This species was an exceedingly important tree for the Indians – they utilized it for a very wide range of applications and it was a central item in their economy. A good plant to grow near the compost heap, aiding the fermentation process. Trees are notably susceptible to honey fungus.
Seed – best sown as soon as it is ripe in a light position in a cold frame. Only just cover the seed and place the pot in a sunny position. Spring sown seed should be surface sown in a sunny position in a cold frame. If the germination is poor, raising the temperature by covering the seed with glass can help. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a cold frame for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. If you have sufficient seed, it can be sown in an outdoor seedbed, either as soon as it is ripe or in the early spring – do not cover the spring sown seed. Grow the plants on in the seedbed for 2 years before planting them out into their permanent positions in the winter.
Inner bark – raw or cooked. Best in the spring. The inner bark can also be dried and ground into a meal and used as a thickener in soups or be added to flour and used in making bread, biscuits etc. Inner bark is generally only seen as a famine food, used when other forms of starch are not available or are in short supply. Sap – raw or cooked. A sweet flavour. Harvested in early spring, before the leaves unfurl, by tapping the trunk. The flow is best on warm sunny days following a hard frost. The sap usually runs freely, but the sugar content is lower than in the sugar maples. A pleasant sweet drink, it can also be concentrated into a syrup or sugar by boiling off much of the water. The sap can also be fermented to make birch beer or vinegar. An old English recipe for the beer is as follows:- “To every Gallon of Birch-water put a quart of Honey, well stirr’d together; then boil it almost an hour with a few Cloves, and a little Limon-peel, keeping it well scumm’d. When it is sufficiently boil’d, and become cold, add to it three or four Spoonfuls of good Ale to make it work…and when the Test begins to settle, bottle it up . . . it is gentle, and very harmless in operation within the body, and exceedingly sharpens the Appetite, being drunk ante pastum.”. Very young leaves, shoots and catkins – raw or cooked. A tea is made from the young leaves and also from the root bark.
Paper birch was often employed medicinally by many native North American Indian tribes who used it especially to treat skin problems. It is little used in modern herbalism. The bark is antirheumatic, astringent, lithontripic, salve and sedative. The dried and powdered bark has been used to treat nappy rash in babies and various other skin rashes. A poultice of the thin outer bark has been used as a bandage on burns. A decoction of the inner bark has been used as a wash on rashes and other skin sores. Taken internally, the decoction has been used to treat dysentery and various diseases of the blood. The bark has been used to make casts for broken limbs. A soft material such as a cloth is placed next to the skin over the broken bone. Birch bark is then tied over the cloth and is gently heated until it shrinks to fit the limb. A decoction of the wood has been used to induce sweating and to ensure an adequate supply of milk in a nursing mother. A decoction of both the wood and the bark has been used to treat female ailments. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Betula species for infections of the urinary tract, kidney and bladder stones, rheumatism.
Other Uses :
Dye; Fuel; Hair; Miscellany; Paper; Pioneer; Waterproofing; Wood.
The thin outer bark is used to make drinking vessels, canoe skins, roofing tiles, buckets etc. This material was very widely used by various native North American Indian tribes, it is waterproof, durable, tough and resinous. Only the thin outer bark is removed, this does not kill the tree. It is most easily removed in late spring to early summer. The outer bark has also been used as emergency sun-glasses in order to prevent snow-blindness. A strip of bark 4 – 5cm wide is placed over the eyes, the natural openings (lenticels) in the bark serving as apertures for the eyes. A brown to red dye can be made from the inner bark. A pioneer species, it rapidly invades deforested areas (such as after a forest fire or logging) and creates suitable conditions for other woodland trees to follow. Because it cannot grow or reproduce very successfully in the shade it is eventually out-competed by the other woodland trees. The tree has an extensive root system and can be planted to control banks from erosion. The bark is a good tinder. An infusion of the leaves is used as a hair shampoo, it is effective against dandruff. The thin outer bark can be used as a paper substitute. It is carefully peeled off the tree and used as it is. A fibre is obtained from the inner bark and another from the heartwood, these are used in making paper. The heartwood fibre is 0.8 – 2.7mm long, that from the bark is probably longer. The branches of the tree can be harvested in spring or summer, the leaves and outer bark are removed, the branches are steamed and the fibres stripped off. Wood – strong, hard, light, very close grained, elastic, not durable. It weighs 37lb per cubic foot and is used for turnery, veneer, pulp etc. It is also used as a fuel. It splits easily and gives off considerable heat even when green, but tends to quickly coat chimneys with a layer of tar.
Known Hazards : The aromatic and aliphatic hydrocarbons in birch tar are irritating to the skin. Do not use in patients with oedema or with poor kidney or heart functions.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.