Assessing the pollination requirements of five commonly planted wildflower species in the southeastern United States

Approximately 86% of all angiosperms rely on an animal vector for successful pollination, yet knowledge of the pollination biology of many native wildflowers is lacking. Understanding the pollination requirements of commonly planted wildflower species could assist development of conservation management plans to promote wildflower diversity and the insect pollinators that visit them. The primary purpose of this study was to evaluate the pollination biology of five commonly planted flowering plant species native to the southeastern United States − Coreopsis lanceolata, Coreopsis tinctoria, Coreopsis tripteris, Echinacea purpurea, and Gaillardia pulchella through an insect exclusion study. We expected that pollinator dependent wildflower species would show reduced seed set and seed weight when excluded from pollinators compared to open pollinated flowers. The insect exclusion treatment had a significant effect on the mean number of seeds produced per flower head in C. lanceolata, C. tinctoria, E. purpurea, yet did not have a significant effect in C. tripteris or G. pulchella. Additionally, mean weights per seed per flower head in the insect exclusion treatment were significantly reduced compared to the open pollinated treatment in C. tinctoria, C. tripteris, E. purpurea and G. pulchella, but not in C. lanceolata. These results suggest that most of the wildflower species we examined are dependent upon insect pollinators to optimize the number and size of seeds produced to successfully complete their life cycles. Future research should focus on determining the major insect pollinators of each wildflower species.