Molecular phylogeny of Ranunculaceae based on internal transcribed spacer sequences

The botanical family Ranunculaceae contains important medicinal plants. To obtain new evolutionary evidence regarding the systematic classification of Ranunculaceae plants, we used molecular phylogenies to test relationships based on the internal transcribed spacer region. The results of phylogenetic analysis of 92 species of Ranunculaceae, Paeoniaceae and Berberidaceae not only supported the monophyly of each of these genera but also suggested a number of additional points: ( 1) All of the inferred genera were clearly rooted together and most supported previous classifications; ( 2) Helleborus, which has sometimes been placed in Helleboroideae, should be retained within Ranunculoideae; ( 3) Adonis, which has sometimes been placed in Ranunculoideae, should be in Helleboroideae; ( 4) Callianthemum, which currently belongs to Ranunculoideae, is separated by a large genetic distance from other genera in this family, suggesting that it should be removed from this family and ( 5) the current generic classification of Ranunculaceae should be revised.