In Poland, Salix myrsinifolia Salisb. reaches the south-western border of the dense geographical range. Therefore, the number of natural stands of this species is limited. The aims of this study were: to evaluate the content of phenolic glycosides in dark-leaved willow bark taken from natural sites, and to investigate the habitat conditions and natural resources of this species in mid-eastern Poland. In the sites of S. myrsinifolia the annual shoots were taken, and the content of phenolic glycosides in willow bark was determined. The plant communities with the share of this species were characterised, and pH, organic matter, macro- and microelements in soils were determined. The bark of the dark-leaved willow is characterised by a very high content of phenolic glycosides and is considered to be potential natural source of salicylates. The plant communities with share of this species were formed spontaneously on highly transformed calcareous fens where peat was mined and on agriculturally developed peatlands. The number of natural stands is small, and gather from natural habitats is limited. Therefore, this species can be a good source of quality raw material during cultivating.

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