Images: ©Jouko Lehmuskallio
Dwarf Birch
Betula nana
- Family: Birch Family – Betulaceae
- Growing form and height: Shrub or dwarf shrub. 0.2–0.8 m (ca. 7–30 in.).
- Flower: Small, greenish to brownish, lacking perianth. Inflorescences dense, pendent catkins formed by numerous, 3-flowered cymes. Male and female flowers in separate inflorescences.
- Leaves: Fairly small, more or less orbicular (roundish), thick, hairless, margins crenate (with rounded teeth). Autumn colour yellow, orange, or red.
- Fruit: A small winged nut (a samara).
- Habitat: Bogs, swamps, fens. In Northern Finland also forests and mountain heaths.
- Flowering time: May–June.
The genus Betula comprises some 40 species, both trees, shrubs, and dwarf shrubs. The trunks of birches are covered with white or darkish, often papery bark. They flower when coming into leaf in the spring. The small flowers are unisexual, the inflorescence a catkin-like, dense compound cyme.
In Southern Finland, the dwarf birch is wholly a mire plant thriving on many different mire types. It hybridises with both the silver birch (B. pendula) and the downy birch (B. pubescens). The hybrids are usually taller than pure dwarf birches and their leaves are larger. The dwarf birch used to be an important source for fuel in Lapland as it burns even when fresh. It is also a constituent part of the vivid autumn colours of the Lappish moorlands.
