Salix polaris (Wahlenb.) - polar willow. It is a prostrate, creeping dwarf shrub, only 2-6 cm high with small rounded-ovate leaves and extensive much-branched system of underground stems. Salix polaris grows in arctic tundra, e.g. in northern Scandinavia, high Arctic islands (Svalbard) northern Siberia. Samples were collected in the years 2007 - 2012 from southern Spitsbergen from the vicinity of the Polish Polar Station in Hornsund. The images of microscopic slides show cross-sections, both above ground (wooden branches) and underground (roots) parts.