Morphological differences in flowers have important evolutionary consequences; they influence the plant's relationship with pollinators and are strongly correlated with sexual function in some breeding systems. Here, I explore the functional relationship between flower morphology and pollination dynamics (e.g. pollen receipt / export) in Solanum carolinense (Solanaceae) and evaluate whether this relationship varies with pollinator taxa. I also investigate if flower morphology determines fruit setting ability of flowers under different pollination regimes. Solanum carolinense has been characterized as having an andromonoecious sexual system where individual plants bear both hermaphroditic and male flowers. This species presents an ideal system to study the relationship between floral morphology, functionality and pollinators because flowers in natural populations vary in their style length and grow in diverse array of environments that vary in their pollinator fauna composition. I conducted a series of greenhouse experiments, pollinator observations and natural population surveys to test these relationships. My results demonstrate that long styled flowers serve as pollen recipients and short styled flowers as pollen donors. However, only bumblebees when (Bombus impatiens) are the pollinators I observe a positive relationship between style length and pollen deposition and a negative relationship with pollen removal. These findings support the female/male interference hypothesis and suggest that when plants are visited by species of species of Bombus, the differences in fitness could favor the evolution of andromonoecy. In contrast, when plants arevisited either by Augochloropsis metallica or Lassioglossum spp. there is no selection for the dimorphism (or any particular style length). I also found that flower morphology, in particular style length, determines the fruit setting ability of the flowers in S. carolinense under different pollination regimes. However, in some flowers sexual functionality varies and does not accord with traditional classification of the flowers. The variation observed for style length, functionality and production of staminate flowers among individuals in natural populations of S. carolinense could be due to variation in abundance and visitation rate of pollinator taxa. Future studies should not neglect taxa-specific plant-pollinator interactions because the evolution of plant breeding systems can be determined by taxa specific interactions
