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: Dwarf Birch

General Information

Betula nana is a sprawling, creeping or uptight, deciduous, much-branched shrub growing up to 100cm tall[, ].
The plant is harvested from the wild for local use as a fod, medicine and source of materials. It is sometimes grown as an ornamental in gardens.
Betula nana is a characteristic, commonly occurring species of Arctic and alpine tundra and subalpine moorlands and bogs throughout its very broad range of distribution. 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

Subarctic and mountainous regions of Europe, from Norway to the Alps, through northern Asia to Siberia; America - Greenland, Northwest Territories

Habitat

Mountain moors, 240 - 840 metres[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	0.30 m
Pollinators	Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

Betula nana is native to areas with very cold winters and often does not do well in milder zones. It can be excited into premature growth in mild winters and this new growth is susceptible to frost damage[].
Succeeds in a well-drained loamy soil in a sheltered position[, ]. Grows well in heavy clay soils. Grows well in moist places or the heath garden[]. Shade tolerant[].
Hybridizes freely with several other members of this genus[, ].
Species in this genus are notably susceptible to honey fungus[].

Edible Uses

Young leaves and catkins - raw[].

The buds and twigs are used as a flavouring in stews[].

Medicinal

The bark is antirheumatic, astringent, lithontripic, salve and sedative[].

Moxa is prepared from the plant and is regarded as an effective remedy in all painful diseases[]. No more details are given, but it is likely that the moxa is prepared from yellow fungous excretions of the wood, since the same report gives this description when talking about other members of the genus[].

A compound decoction of the leaves has been used in the treatment of stomach ache and intestinal discomfort[].

Agroforestry Uses:

Plants can be used for ground cover, forming a spreading hummock up to 1.2 metres across[].

Other Uses

An infusion of the plant is used as a hair conditioner and dandruff treatment[].

A yellow dye is obtained from the leaves[].

The plant has been used as a tinder, even when wet, and for cooking fires when there is a lack of larger wood[]. It is likely that the bark was used for tinder[].

The stems are used for winter fuel[].

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[, , , ].
Layering. The plants often self-layer.