INTERFAMILIAL RELATIONSHIPS OF THE ASTERACEAE - INSIGHTS FROM RBCL SEQUENCE VARIATION

Nucleotide sequences of the chloroplast gene rbcL were analyzed to exa mine 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 f amilies, the Goodeniaceae and Calyceraceae, as the sister group to the Asteraceae. In addition, a strongly supported major monophyletic clad e consisting of Asteraceae, Goodeniaceae, Calyceraceae, Corokia (Corna ceae sensu Cronquist), Menyanthaceae, Lobeliaceae, and Campanulaceae w as found. These results clearly distance from the Asteraceae certain g roups previously considered closely related; moreover, the results sup port alternative hypotheses of affinity that were based upon floral an d inflorescence morphology, biogeography, pollen morphology, chemistry , and pollen-presentation mechanisms.