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: Grey Birch

General Information

Betula populifolia is a broadly pyramidal, deciduous tree, usually with several trunks; it can grow up to 10 metres tall[].
The tree is harvested from the wild for use as a food, medicine and source of materials. It is sometimes grown as an ornamental and can be used as a pioneer species for establishing native woodland and for reclaming land such as mine spoil tips.
Betula populifolia is a very common species in the northeastern portion of its geographic range. 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

None known

Botanical References

, ,

Range

Eastern N. America - Ontario to Nova Scotia, south to South Carolina

Habitat

Rocky or sandy open woods, moist to dryish slopes, old fields, and waste places; at elevations from 100 - 600 metres[]. Margins of swamps and ponds, also in dry sandy or gravelly barren soils, growing well in poor almost sterile soils[, ].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	8.00 m
Pollinators	Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

Succeeds in a well-drained loamy soil in a sunny position[, ]. Tolerates most soils doing well on poor ones[] and on heavy clays.
A fast growing tree, though it rarely lives longer than 50 years[, ]. It is a pioneer species of abandoned fields, burnt-over lands, cleared woodlands etc[, ]. A fairly wind-tolerant plant[], but it is shallow-rooted and older trees are often uprooted by winds and heavy snow in the wild[].
Stands of this tree can be cut for firewood at comparatively frequent intervals because of its ability to regenerate quickly - since the wood burns well, the tree is therefore often used for fuel[].
Hybridizes freely with several other members of this genus[, ], especially with Betula papyrifera[].
A good plant to grow near the compost heap, aiding the fermentation process[].
Species in this genus are notably susceptible to honey fungus[].

Edible Uses

Inner bark - cooked or dried and ground into a meal. The meal can be used as a thickener in soups etc, or be added to flour when 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 - sweet. Harvested in early spring, before the leaves unfurl, by tapping the trunk. The flow is best on warm days that follow frosty nights. The sap is drunk as a sweet beverage or it 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.'[].

Medicinal

The bark is astringent abd emetic. A decoction has been used as a wash to treat bleeding piles[, ].
Scrapings of the inner bark have been used to treat swellings in infected cuts[, ].

Agroforestry Uses:

A pioneer species, readily invading old fields, burnt-over or cleared land and providing suitable conditions for other woodland trees to become established[]. It is an excellent crop for very poor soils, where it grows rapidly and affords protection to the seedlings of more valuable and slower-growing trees[]. Since this species is short-lived and not very shade tolerant, it is eventually out-competed by these other trees[].
This species is an early colonizer of rocky, open sandy woods, old fields, road cuts and burned areas. It springs up in vast numbers after forest fires and then provides shade and shelter for seedlings of more valuable species until finally overwhelmed by them[].
It is a good hardwood species for use in revegetation of mine spoils and other disturbed areas. It has been planted successfully on acid coal mine spoils in Pennsylvania[].

Other Uses

The wood is light in weight, close-grained, soft, weak, not durable[, , , ]. It weighs 36lb per cubic foot[]. It is easily worked with tools and is an excellent wood for turning. It is used for woodenware such as spools, clothespins and novelties[]. Unimportant commercially, the wood is used locally for making clothes pegs, spools, pulp etc[, , ].
The wood is quite commonly burnt as a fuel and is also used to make charcoal[, , ].

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[, , , ].