The Role of Phenotypic Plasticity among Largeleaf Pennywort (Hydrocotyle bonariensis) Populations Occupying Different Habitats in Coastal Georgia

Hydrocotyle bonariensis (Largeleaf Pennywort) is a clonal perennial herb often found within its native range in multiple habitats that may differ in environmental factors. Plants can respond to the local environment through phenotypic plasticity, which results in different phenotypes in response to different environmental factors. The aim of this study was to determine the role of phenotypic plasticity in the ability of Largeleaf Pennywort to occupy multiple habitats in coastal Georgia, specifically coastal sand dune and inland coastal plain habitats. We assessed leaf morphology for plants in both their native habitats and also under greenhouse conditions in response to different soils and salt spray. Results showed marked differences in leaf morphology between plants in the different native habitats, and the greenhouse study suggested that plants responded plastically to soil through tissue modifications related to water storage. These results indicate that phenotypic plasticity likely plays an important role in the ability of Largleaf Pennywort to occupy multiple habitats in coastal Georgia.