The article covers the results of a survey of the vascular flora of the peat-bogs and forest swamps of the Kotlina depression in southern Poland. Unexpected concentrations of calcicolous plants are shown to exist and the factors governing their presence are discussed. The discovery of previously unexpected glacial relicts is also examined in the context of the area’s importance in phytogeographical studies of Eastern Europe. A number of observed, but unexplained, discrepancies in the distribution of a small number of relic species have been identified and are given as possible worthwhile lines of further research.