CHUMLEY, TIMOTHY W.†*, JOSÉ L. PANERO†, STERLING C. KEELEY‡, AND ROBERT K. JANSEN†. †Section of Integrative Biology, School of Biological Sciences, University of Texas at Austin, Austin, TX 78712; ‡Dept. of Botany, University of Hawaii, 3190 Maile Way, Honolulu, HI 96822-2279. - A phylogeny of the Ecliptinae (Asteraceae: Heliantheae) as inferred from internal transcribed spacer (ITS) sequences, and the origin of Lipochaeta.
As part of a study looking at relationships within the Hawaiian
endemic genus Lipochaeta DC., a phylogenetic analysis of the
subtribe Ecliptinae s. s. (Asteraceae: Heliantheae) using sequences of
the internal transcribed spacer (ITS) region of nuclear ribosomal DNA
was conducted to explore the potential polyphyly of the genus. Two
well supported clades were found. A clade containing the "core
Ecliptinae" (Wedelia, Zexmenia, Oyedaea, and Elaphandra)
agrees with results of a previous cpDNA restriction site study,
although topological relationships within the clade and its placement
in the tree are not well supported by bootstrapping. A much more
robust clade consisting of Wulffia, Perymenium, Wollastonia,
Melanthera, and Lipochaeta shows a sister relationship
between Wollastonia and Melanthera, and these are sister
to Lipochaeta. While some previous workers have suggested independent
origins of the two sections of Lipochaeta from possibly
different wedelioid ancestors, Lipochaetaappears to be
monophyletic. An expanded sampling of genera in the subtribe is
currently in progress.
Key words: Ecliptinae, Heliantheae, ITS, Lipochaeta, phylogeny