Betula nana L.

A low shrub reaching no more than 1 m in stature, Betula nana is easily identified by its diminutive habit, more-or-less circular leaves with relatively few rounded teeth, and hairy twigs with few glands. The species was described by Linnaeus from Lapland where he encountered it during his first major field trip in 1732, a tour of Sweden and northern Russia that covered nearly five thousand kilometres (Blunt 1971). It is a major component of arctic tundra vegetation, extending to the shores of the arctic sea from Greenland through northern Europe to west Siberia, but it also occurs a long way further south in mountain ranges such as the Alps and Carpathians in Europe. It may be the longest lived of all birchs: a stem with 147 growth rings has been recorded from southeast Greenland, and its potential to layer means that some individual clones could well be very ancient (De Groot, Thomas & Wein 1997).

These small shrubs are not commonly cultivated as they often develop a straggly habit, and do not have particularly showy catkins. Outside their natural range, they are best grown on humus-rich soils. Being largely arctic or high mountain plants of immature or peaty soils, they do not thrive on clay, but if grown in full sun in a cool climate they make neat, attractive small shrubs and could be potential subjects for bonsai or a stone trough. Betula nana is easily propagated by seed, but is largely self-incompatible, meaning that more than one clone needs to be grown for seed production. Cuttings root easily and produce larger plants more rapidly.