The tribe Exostyleae is an early-branching monophyletic clade of the flowering plant subfamily Faboideae (or Papilionaceae) that are mostly found in Neotropical rainforests.

[2] This clade is composed of 6 genera, most of which were traditionally assigned to the tribe Swartzieae.

[4][5] However, recent molecular phylogenetic analyses circumscribed these six genera into a strongly supported monophyletic clade.

[1][2][6][7][8][9] Synapomorphic traits that unite the members of this clade include non-papilionate flowers, "serrate and sometimes spinescent leaflet or leaf margins, standard position variable in the floral bud, basifixed anthers, and drupaceous fruits".

[1][2][6][7] They are also united by wood anatomy, sharing an "uncommon presence of crystals in ray cells",[1][10][11] and floral ontogeny, sharing "unidirectional initiation of five sepals, simultaneous initiation of petals, and[…]unusual antepetalous stamens initiating before the antesepalous ones.