Species of the genus Betula are a difficult group taxonomically because of their high vegetative variability and frequent hybridization. Many species have been founded on only slight differences and many of these have subsequently been reduced to synonymy. Many morphologic and cytologic studies have attempted to deal with variation within the genus or its subgroups. Species of Betula form a polyploid series, with chromosome numbers of 2 n = 28, , , , and 112, plus additional numbers in some hybrids.

Common Name: Cherry Birch

General Information

Betula lenta is a deciduous tree with a narrow, open crown; it can grow up to 20 metres tall. The bole is straight and cylindrical[].
The tree is harvested from the wild for a wide range of traditional uses as a food, medicine and source of materials. It is a dominant tree in the northern hardwood forests of the northern Appalachians in the US, where it is a valuable commercial source of timber. It used to be the chief commercial source of wintergreen oil (methyl salicylate), which is distilled from its wood, but this oil is now produced synthetically[].
Betula lenta is a widespread, commonly encountered tree found in the eastern United States of America and Canada. The population is stable and there are no known threats that are or will adversely affect this species in the foreseeable future. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

The essential oil obtained from the bark contains 97 - 99% methyl salicylate. This is very toxic when taken orally, and it can also be absorbed through the skin, resulting in human fatalities. As little as 4, 700 mg can be fatal in children[].

Botanical References

, ,

Range

Eastern N. America - Ontario to Maine, south to Alabama and Georgia

Habitat

Rich woodlands, preferring north-facing slopes and moist soils[, ]. It is also found on rocky soils[]. Rich, moist, cool forests, especially on protected slopes, to rockier, more exposed sites; at elevations up to 1,500 metres[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	24.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

An easily grown plant, it succeeds in a well-drained loamy soil in a sheltered position[, ]. Grows well in heavy clay soils. Dislikes wet soils[]. Shade tolerant[]. Cherry birch is said to tolerate an annual precipitation of ca 60 to 150cm, an average annual temperature range of 5 to 12°C, and a pH of 4.5 to 7.5[].
Hybridizes freely with several other members of this genus[], especially with Betula alleghaniensis[]..
The bruised foliage has a strong smell of wintergreen[].
A good plant to grow near the compost heap, aiding the fermentation process[].
Trees can be coppiced on a cycle of 5 years or more[].
Species in this genus are notably susceptible to honey fungus[].

Edible Uses

Inner bark - cooked or dried and ground into a powder[, , ]. Sweet and spicy[]. The dried inner bark can be used as a thickener in soups etc or can be added to flour when making bread 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[, ]. It is harvested in early spring, before the leaves unfurl, by tapping the trunk. The flow is best on sunny days following a heavy frost. A delicious drink, it can also be concentrated into a syrup or sugar[]. The sap can 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.'[].

The dried leaves and bark from the larger roots are a delightful tea substitute[, ].
A wholesome, agreeable tea is made from the essential oil contained in the inner bark and twigs[, , ]. This essential oil is also used as a wintergreen flavouring in foods[].

Medicinal

The bark is anthelmintic, astringent, diaphoretic, diuretic and stimulant[, ]. A tea made from the bark is used in the treatment of fevers, stomach aches and lung ailments[, ], it is said to be an excellent tonic in cases of dysentery and to be useful in the treatment of gravel and female obstructions[].

An essential oil distilled from the bark is anti-inflammatory, analgesic and rubefacient[]. It is used in the treatment of rheumatism, bladder infections, neuralgia etc[]. The oil, called 'oil of wintergreen', used to be produced commercially, but it is now manufactured synthetically[].

A tea made from the twigs is used in the treatment of fevers[].

The leaves can be chewed or used in an infusion in the treatment of dysentery[].

Other Uses

An essential oil is obtained from the bark and twigs, it is distilled in quantity and is an item of commerce[]. It can be used medicinally, as a food flavouring, as an ingredient in cosmetic shampoos and also to make a wholesome tea[, , , , ]. The oil, when decolourized, is similar to 'Oil of Wintergreen' (obtained from Gaultheria procumbens) and is considered to be of superior quality[]. The tree is coppiced every 5 years and all parts are distilled for the oil[]. The tree grows up to 3 metres tall in this 5 year period[]. The greatest yield of oil is obtained if the tree is harvested in the summer[].
The oil distilled from the wood is insect repellent[].l
The bark contains up to 16% tannin[].
The thin outer bark is waterproof and has been used as the outer cladding on dwellings, canoes etc[]. It has also been used to make baskets, dishes, buckets etc[].
Wood - very strong, close grained, hard, heavy. The wood is richly marked[], it weighs 40lb per cubic foot and is exploited commercially for making floors, furniture, tools etc[, , , , , ]. It makes an excellent fuel[, , , ].
it is heavy, very hard and strong, with a silky sheen, close-grained and polishable. Both are economically important timber species providing lumber and veneer for use in the manufacture of furniture, cabinets, boxes, plywood, panelling and also in ship and boat building. Betula lenta pulp is used in various products such as box boards, book and newsprint, and corrugated paper. Historically, B. lenta was harvested to produce wintergreen oil (methyl salicylate) that was distilled from it. Today wintergreen oil is produced chemically using wood alcohol and salicylate[].

Propagation

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[, , , ].