Origin of Spergularia ×kurkae, a hybrid between the rare endemic S. echinosperma and its widespread congener S. rubra

The origin of Spergularia ×kurkae, a presumed tetraploid hybrid between diploid central-European endemic S. echinosperma and its widespread tetraploid congener S. rubra, was investigated using molecular tools. Sequencing of the internal transcribed spacer (ITS) confirmed the hybrid origin of S. ×kurkae and the parentage. As incomplete concerted evolution of the ITS region was observed in nearly all individuals of S. ×kurkae, it is probable that S. ×kurkae is a young taxon. We speculate that it might have evolved as a result of human-mediated introduction of S. rubra into fishponds