Interfamilial Relationships of the Asteraceae: Insights from rbcL Sequence Variation

Nucleotide sequences of the chloroplast gene rbcL were analyzed to examine relationships among the large, distinctive family Asteraceae and eight putatively closely related families. Phylogenetic analysis of a total of 24 sequences of rbcL identified a lineage consisting of two families, the Goodeniaceae and Calyceraceae, as the sister group to the Asteraceae. In addition, a strongly supported major monophyletic clade consisting of Asteraceae, Goodeniaceae, Calyceraceae, Corokia (Cornaceae sensu Cronquist), Menyanthaceae, Lobeliaceae, and Campanulaceae was found. These results clearly distance from the Asteraceae certain groups previously considered closely related; moreover, the results support alternative hypotheses of affinity that were based upon floral and inflorescence morphology, biogeography, pollen morphology, chemistry, and pollen-presentation mechanisms