In Poland there are 163 lakes (a major percentage in Western Pomerania) which thanks to its specific physical and chemical properties and unique vegetation are termed lobelian lakes. These are mostly small reservoirs without any tributaries which due to poor and small watersheds have retained the status of oligotrophic lakes. Vegetation occurring there includes boreal and Atlantic relicts, classified as rare and protected species, e.g. Lobelia dortmanna, Isoetes lacustris and Litorella uniflora. These species have special habitat and nutrition requirements and they grow only in lakes with the low calcium content. The article provides characteristics of these unique ecosystems.