Molecular and morphological analyses of EuropeanAconitum species (Ranunculaceae)

The systematics of the yellow-floweredAconitum lycoctonum species complex (Ranunculaceae) has long been considered difficult because of high morphological variability and hypothesized hybridization. To elucidate the systematic value of these taxa, and to study their phylogeny in a broader context, we studied all species of the subgenusLycoctonum from Europe and the Caucasus Mountains and the European species of the subgen.Aconitum. We sequenced the ITS region and the chloroplast intergenic spacerpsbA-trnH and conducted parsimony analyses. We also measured morphological characters from 19A. lycoctonum populations. The two subgenera in Europe are clearly separated but hybridization between subgenera might have taken place in the past. Sequence variation withinA. lycoctonum and among all taxa of subgenusLycoctonum was very low and probably the result of recent speciation, leading to one morphologically highly variable species in which color morphs could be seen as subspecies. There was high morphological variability within and among populations and the morphological characters have no value as systematic characters.