This tribe does not currently have a node-based, phylogenetic definition, but it can be distinguished by the following morphological synapomorphy: "an ornithophilous floral syndrome in which the calyx and hypanthium are enlarged, the petals thickened and often red or orange, the standard often distinctly large, the lower petals undifferentiated or sometimes highly reduced, and the stamens and gynoecium exserted."[2][1] Also, members of this tribe accumulate iminosugars in their leaves, whereas other members of the ADA clade do not.[6]
^ abcCardoso, D.; de Queiroz, L. P.; Pennington, R. T.; de Lima, H. C.; Fonty, E.; Wojciechowski, M. F.; Lavin, M. (2012). "Revisiting the phylogeny of papilionoid legumes: new insights from comprehensively sampled early-branching lineages". Am J Bot. 99 (12): 1991–2013. doi:10.3732/ajb.1200380. PMID23221500.
^Doyle, Jeff J.; Doyle, Jane L.; Ballenger, Julie A.; Dickson, Elizabeth E.; Kajita, Tadashi; Ohashi, Hiroyoshi (1997). "A phylogeny of the chloroplast gene rbcL in the Leguminosae: taxonomic correlations and insights into the evolution of nodulation". Am J Bot. 84 (4): 541–554. doi:10.2307/2446030. JSTOR2446030. PMID21708606.