Molecular phylogenetics of the species‐rich neotropical genus Swartzia (Leguminosae, Papilionoideae) and related genera of the swartzioid clade

Swartzia (ca. 180 spp.) is a characteristic and diverse element of neotropical rainforest tree communities. As such, it has been identified as a focal group in studies of evolutionary diversification and community assembly in rainforests. However, progress is impeded by the lack of a phylogenetic hypothesis for the genus and its close relatives, which together constitute the descendents of one of the first branches of the papilionoid phylogeny. Here we present a molecular phylogenetic study with extensive sampling of species of Swartzia and with complete sampling of genera of the “swartzioid” clade. The results, based on analysis of chloroplast ( atpB–rbcL, trnL intron, and trnL–F ) and nuclear (AAT1 and ITS) DNA sequences, add substantially to our understanding of relationships within this diverse group and call for taxonomic changes, particularly within Swartzia . The monophyly of a redefined Swartzia is weakly to moderately supported. Within Swartzia , the analyses identify 11 nonoverlapping subclades, few of which correspond exactly to previously published taxa. The analyses support the recent segregations of Bobgunnia from Swartzia and of Trischidium from Bocoa , as well as the resurrection of the monospecific genus Fairchildia . The analyses identify a “core swartzioid” clade comprising the remainder of Swartzia, Bocoa , and Candolleodendron .