GENERIC RELATIONSHIPS IN THE DICHROSTACHYS GROUP (LEGUMINOSAE, MIMOSOIDEAE) - EVIDENCE FROM CHLOROPLAST DNA RESTRICTION SITES AND MORPHOLOGY

Data from chloroplast DNA restriction sites and morphology are combine d in a phylogenetic analysis of six genera in the Dichrostachys and Le ucaena groups. Desmanthus is demonstrated to be monophyletic, which co ntrasts with previous morphological studies in which it was paraphylet ic to Neptunia. The monotypic genus Calliandropsis from central Mexico is sister to the Old World genus Dichrostachys, a result consistent w ith all previous analyses, as well as with ecological evidence. The cl adistic analysis shows that the Dichrostachys group is not monophyleti c; Desmanthus is more closely related to Leucaena and Schleinitzia tha n it is to the other genera in the Dichrostachys group. Based on these data, the Leucaena group is recircumscribed to include the genera Des manthus, Leucaena, and Schleinitzia, and the Dichrostachys group to in clude Calliandropsis, Dichrostachys, Gagnebina, and Alantsilodendron. The position of Neptunia relative to the other genera is ambiguous, an d it is placed incertae sedis pending more conclusive evidence about i ts position in the Mimosoideae.