Molecular phylogenetic studies of 123 genera belonging to tribes Helenieae, Heliantheae and Eupatorieae of the HHE clade reveal novel relationships for several members of these tribes. The genera Phaneroglossa (Senecioneae) and Inula (Inuleae) were chosen as outgroups. Parsimony analysis of the data matrix produced 8640 trees of 11090 steps (CI 0.5654 excluding uninformative characters, RI 0.6605). After analysis of the data matrix and the resulting phylogenetic hypothesis we conclude that the genera Athroisma and Blepharispermum are not members of the HHE clade and should either be recognized as a separate tribe or reincorporated into the Inuleae, as they share numerous synapomorphies with the outgroup. The basalmost lineage of the HHE clade contains the genera Psathyrotes, Marshallia, Helenium, Hymenoxys, and Psilostrophe. These genera, along with a few others classified by previous authors in either subtribes Marshalliinae or Gaillardiinae, are here included in a narrowed interpretation of tribe Helenieae. Dahlia and Coreopsis are sister and constitute the next sublineage to diverge. Their basally divergent position is somewhat surprising although morphologically they are a very distinct group that we recognize as tribe Coreopsideae. In some of the most parsimonious trees we observed that a majority of the epaleate genera centered about Bahia, Chaenactis, and Hymenopappus and previously classified in tribe Helenieae s. l., the traditional helianthoid taxa Polymnia, Enydra, and subtribe Neurolaeninae are grouped in a clade sister to a large clade containing most members of tribe Heliantheae, Eupatorieae and the tarweeds and relatives. In the strict consensus tree this intriguing clade collapses leaving a polychotomy with the genera Varilla and Jaumea as single lineages, Enydra sister to Neurolaeninae, the epaleate helenioid genera grouped in a clade with moderate support, and Polymnia sister to Oxypappus.

Key words: Asteraceae, chloroplast DNA, Eupatorieae, Helenieae, Heliantheae, phylogenetics