Morphological traits in keel flowers of Papilionoideae (Fabaceae) and their relationships with the pollination mechanisms.

Several floral traits in Papilionoideae (Fabaceae) have been correlated to certain pollination mechanisms. To test this hypothesis, we analyzed 20 qualitative and 21 quantitative floral traits of 17 species of Papilionoideae with keel flowers from various tribes and genera native to Salta, Argentina, which are representative of the four general pollination mechanisms described for the subfamily. We performed field and laboratory studies, including description of morphology, micro-morphology, position, size, and synorganization of all floral organs. Correlation between floral traits and a particular pollination mechanism was evaluated through a principal component analysis (PCA). According to our results, species with the same pollination mechanism share similar qualitative and quantitative traits, the latter being the most relevant, according to our statistical analysis. [ABSTRACT FROM AUTHOR]