Restriction map variation has been assayed in the slowly evolving chlo
roplast DNA (cpDNA) inverted repeat regions of 43 genera of the large
and economically important legume tribe Phaseoleae and representatives
of several allied tribes. Cladistic analyses of these data indicate t
hat several plastome groups correspond well to subtribes recognized la
rgely on the basis of morphological variation. Based on these cpDNA da
ta, the tribe as a whole does not appear to be monophyletic, a result
in accordance with current, morphologically-based hypotheses. Plastome
s of several genera belonging to subtribes considered basal within Pha
seoleae have as their sister groups plastomes of non-Phaseoleae tribes
, notably Millettieae, the tribe considered to represent the ancestral
stock from which diverse elements of Phaseoleae were derived. More un
expectedly, plastomes of the tribe Desmodieae fall within the clade th
at includes the most derived chloroplast genomes of Phaseoleae.