The tribe Swartzieae is an early-branching monophyletic clade of the flowering plant subfamily Faboideae or Papilionaceae. Traditionally this tribe has been used as a wastebasket taxon to accommodate genera of Faboideae which exhibit actinomorphic, rather than zygomorphic floral symmetry and/or incompletely differentiated petals and free stamens.[2][3] It was recently revised and most of its genera were redistributed to other tribes (Amburaneae, Baphieae, and Exostyleae).[2][4][5] Under its new circumscription, this clade is consistently resolved in molecular phylogenies.[2][4][6][7][8][9][10][1][11] Members of this tribe possess "non-papilionate swartzioid flowers[…]largely characterized by a tendency to lack petals combined with a profusion and elaboration of free stamens"[2][4] and a "lack of unidirectional order in the initiation of the stamens".[1] They also have "complete or near complete fusion of sepals resulting from intercalary growth early in development, relatively numerous stamens, and a single or no petal, with other petals not at all apparent in development."[12] The tribe is predicted to have diverged from the other legume lineages 48.9±2.8 million years ago (in the Eocene).[10]
The members of this clade are distinguished by "a nearly actinomorphic androecium with basifixed anthers, exarillate seeds, and a tendency toward alternate leaflets."[4][1] They occur mainly in neotropical, seasonally-dry tropical woodlands.[4]