This shrub is one of those which, in addition to the dwarf birch B. nana, make up the sub-genus of dwarf birches. However, it grows larger than B. nana, to about 2 metres. The bark is greyish-white and the branches red-brown. The leaves are small and more oval than in B. nana. The catkins are fairly thick and erect, the females becoming fuzzy seed catkins after pollination.