Phylogenetic relationships of basal papilionoid legumes based upon sequences of the chloroplast trnL intron

The Swartzieae, Sophoreae, Dipterygeae, and Dalbergieae are considered the most basal tribes of the subfamily Papilionoideae (Leguminosae). Nucleotide sequences from the chloroplast trnL intron for the majority of genera of t hese tribes were analyzed cladistically together with placeholder represent atives of more derived tribes. Preliminary results indicate radical changes are necessary for papilionoid classification because Swartzieae, Sophoreae , and Dalbergieae are polyphyletic. Their constituent genera are mixed in a series of monophyletic groups, many of which have never been proposed prev iously, and the relationships amongst which are poorly resolved. Some of th ese groups, such as the genistoid and dalbergioid clades, are species-rich because they contain major papilionoid radiations. In other cases, putative ly basal genera form small clades with no derived taxa included. There is w eak evidence that Bobgunnia, Swartzia, Cyathostegia, Bocoa, and Ateleia (al l Swartzieae) may be the sister group to all other papilionoids, and that a large clade is congruent with a 50kb inversion in the chloroplast large si ngle copy (LSC) region.