Mort, M.E., C.P. Randle, R.T. Kimball, M. Tadesse, and D.J. Crawford. 2008. Phylogeny of Coreopsideae (Asteraceae): Insights from nuclear and plastid sequences. Taxon. 57: 109-120.

 

A phylogenetic study of tribe Coreopsideae (Asteraceae) was conducted using sequences from two plastid regions matK and the trnL-trnF spacer, and nuclear ITS. Analyses of the plastid and ITS datasets result in similar topologies; thus these data partitions were combined and reanalyzed, resulting in a more highly resolved estimate of phylogeny. The plastid, ITS and total evidence trees indicate that the two largest genera of the tribe, Bidens and Coreopsis, are not monophyletic. Total evidence reveals several relationships that are not recovered by analyses of the individual data partitions, including a clade of four insular genera sister to a clade consisting of two sections of Mexican Coreopsis, and the genera Henricksonia, and Heterosperma. Furthermore, the annual, monospecific genus Dicranocarpus and Dahlia are recovered as sisters. The nuclear and plastid data partitions disagree with regard to the monophyly of Coreopsis sect. Pseudoagarista, with ITS placing the Mexican and South American members in distant clades whereas plastid sequences show them as sister groups. There is hard incongruence between the position of the enigmatic Coreocarpus congregatus in the plastid and nuclear trees. Comments are provided on possible diagnostic characters for clades in the total evidence tree.