In this thesis, different speciation processes were studied that were involved in the origin of V. stagnina and its closest relatives. Phylogenetic analyses of the CHS intron showed that... Show moreIn this thesis, different speciation processes were studied that were involved in the origin of V. stagnina and its closest relatives. Phylogenetic analyses of the CHS intron showed that hybridization and polyploidisation played an important role during speciation and that Viola stagnina is one of the parental species of the alloploid species V. canina, V. lactea and V. pumila and the parental species of the autotetraploid V. elatior. The analyses also confirmed that the closest relatives of V. stagnina were the other arosulate violets V. canina, V. elatior, V. pumila and V. lactea. In an attempt to settle a debate among Dutch botanists about the taxonomic status of V. stagnina var. lacteoides, the morphological and genetic variation within V. stagnina were studied using AFLP, morphometrics analyses, a common garden experiment, and a crossing experiment. The genetic and morphological differences found support for the recognition of the infraspecific taxon V. stagnina var. lacteoides. The nomenclatural studies carried out resulted in a recommendation to formally reject the ambiguous name V. persicifolia for the European Fen Violet and use the name V. stagnina, instead. To bring the common name into line with the usage in Belgium, it is also recommended to change the Dutch common name from Melkviooltje into Vals melkviooltje. Show less