Betula papyrifera

• Paper Birch

Sap - raw or cooked. A sweet flavour^[2]. Harvested in early spring, before the leaves unfurl, by tapping the trunk^[1]. 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^[3]. A pleasant sweet drink, it can also be concentrated into a syrup or sugar by boiling off much of the water[183, K]. The sap can also be fermented to make birch beer or vinegar^[4]. 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.\"^[5]. Very young leaves, shoots and catkins - raw or cooked^[1][4].

The outer bark has also been used as emergency sun-glasses in order to prevent snow-blindness^[3]. 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^[3]. A brown to red dye can be made from the inner bark^[6]. 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^[3]. The tree has an extensive root system and can be planted to control banks from erosion^[3]. The bark is a good tinder^[1]. An infusion of the leaves is used as a hair shampoo, it is effective against dandruff^[11][1]. The thin outer bark can be used as a paper substitute. It is carefully peeled off the tree and used as it is^[1]. A fibre is obtained from the inner bark and another from the heartwood, these are used in making paper^[12]. The heartwood fibre is 0.8 - 2.7mm long, that from the bark is probably longer^[12]. 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^[12].

The bark is antirheumatic, astringent, lithontripic, salve and sedative^[1]. The dried and powdered bark has been used to treat nappy rash in babies and various other skin rashes^[6]. A poultice of the thin outer bark has been used as a bandage on burns^[6]. A decoction of the inner bark has been used as a wash on rashes and other skin sores^[6]. Taken internally, the decoction has been used to treat dysentery and various diseases of the blood^[6]. 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^[6].