The adaptation of Dianthus carthusianorum L. (Caryophyllaceae) to growth on a zinc-lead heap in southern Poland

Plants of Dianthus carthusianorum from a calamine (zinc-lead) waste heap and from unpolluted stands were compared in the field and under controlled laboratory conditions. It was found that the waste-heap plants differed significantly from those in the normal population in respect to the following morphological traits: lower weight of aerial parts, shorter and narrower leaves, smaller number of leaves per plant. In combination with shorter, less numerous shoots, these features reduce the transpiration area of the plants. The general habit (predominance of forms with short and trailing shoots) of the waste-heap population points to adaptation to a xeric environment. Under controlled conditions all of the above traits were maintained through three successive generations. They are thus genetically controlled. Root tolerance tests showed that the waste-heap plants had higher tolerance to zinc and lead. These results indicate that strong selection processes have generated a clear ecotypical differentiation for heavy metal tolerance and drought tolerance in a zinc-lead-rich waste-heap population of D. carthusianorum (variety).