Floral Organogenesis and Morphogenesis of<i>Staphisagria</i>(Ranunculaceae): Implications for the Evolution of Synorganized Floral Structures in Delphinieae

Premise of research. Floral synorganization is a structural feature many speciose angiosperm taxa and considered morphological innovation paving the way for evolutionary diversification. Staphisagria sister to remaining Delphinieae, only lineage Ranunculaceae characterized by zygomorphic flowers. We aim at providing description floral organogenesis morphogenesis in both species, presenting disparity Delphinieae hyperorgans phylogenetic framework, proposing scenario likely developmental pathways underlying different types Delphinieae.Methodology. carried out morphological, anatomical, studies on flowers S. macrosperma picta.Pivotal results. Synorganization complex as whole involves flower dorsoventralization, nesting spurs, postgenital fusion petals, formation shared cavity. From choripetalous ancestor, late partial among dorsal petals evolved once or twice tribe.Conclusions. The includes nested spurs parlors. These key innovations, unique angiosperms, probably led diversification this species-rich tribe Northern Hemisphere. lengths inner (nectariferous) parlors determine range pollinators able collect nectar. traits could be used revise circumscription taxonomic groups within should taken into account when examining possible coevolution between their pollinators. Integrating new knowledge about hyperorgan will essential future research taxonomy, evo-devo, pollination ecology Delphinieae.