Vallejo-Marin, M., & M. D. Rausher. in press. The role of male flowers in andromonoecious species: Energetic costs and siring success in Solanum carolinense. Evolution

Abstract

Two non-mutually exclusive hypotheses regarding the benefits of andromonoecy (producing perfect and female-sterile flowers on the same plant) are tested using Solanum carolinense. Results indicate that: (1) staminate flowers are cheaper to produce than perfect flowers, even after correcting for their relative position in the inflorescence; (2) the resources saved by producing staminate flowers are not re-allocated to other fitness enhancing functions; and (3) the main morphological characteristic of staminate flowers, pistil reduction, does not increase either pollinator visitation or siring success of open-pollinated plants. These results indicate that neither the resource savings hypothesis nor the increased pollen donation hypothesis explain the evolution and maintenance of andromonoecy in S. carolinense.

Keywords: andromonoecy, flower size, pollen donation, resource allocation, siring success, Solanum carolinense.