RECLASSIFICATION OF ACTAEA TO INCLUDE CIMICIFUGA AND SOULIEA (RANUNCULACEAE) - PHYLOGENY INFERRED FROM MORPHOLOGY, NRDNA ITS, AND CPDNA TRNL-F SEQUENCE VARIATION

Phylogenetic analyses using parsimony were performed on three independ ent data sets to test generic relationships between Actaea, Cimicifuga , and Souliea. Analyses of morphology and nuclear ribosomal DNA ITS we re performed on 23 species of Cimicifuga, 4 species of Actaea, and the single species of Souliea. Analysis of chloroplast DNA tmL-F was appl ied to the same species, less two of Cimicifuga. The outgroup taxa Era nthis and Anemonopsis both resolved outside the ingroup in all parsimo ny analyses, whereas Souliea resolved within it. Jukes-Cantor pairwise sequence distances confirm Eranthis and Anemonopsis to be most distan t. Souliea distances are comparable with those of taxa within the Acta ea-Cimicifuga assemblage. A strongly supported monophyletic clade incl uding all studied species of Actaea, Cimicifuga, and Souliea was found in all analyses. Evidence presented here allows a broader concept of Actaea to be adopted, reverting to the circumscription of Linnaeus in 1753. Seven sections, based on clades found in the total analysis, cou ld be defined by morphological characters: A, sect. Actaea, sect. Podo carpae, sect. Cimicifuga, sect. Dichanthera, sect. Oligocarpae, sect. Pilyrosperma, and sect. Souliea. One species, A. taiwanensis, is newly described and 23 new combinations are made in the ranks of section, s pecies, and variety. Keys are provided to identify taxa at all ranks w ithin the revised circumscription of Actaea. Maps showing the distribu tions of all seven sections and their constituent species are presente d. Phytogeographic patterns suggest a Tertiary origin for the newly re defined genus, with species surviving in refugia during the glacial pe riods of the Pleistocene.