Betula nana (L.) - dwarf birch. Shrub and dwarf shrub up to 1 m high with extensive much-branched system of stems, small rounded leaves with bluntly toothed margin. Betula nana grows in arctic and cool temperate regions of northern Europe and Asia and in Canada, Alaska and Greenland. Samples were collected in 2015 from northern Scandinavia from the vicinity of Tromsø (Norway). The images of microscopic slides show parts of cross-sections of stems.