Nectary and leaf deployment variation of the exotic ant-plant Ricinus communis L. (Castor Oil Plant) across temperate and tropical landscapes

Abstract

Invasive species are recognized to be a major component of global environmental change, and attention and research has been diverted to understanding the characteristics of invaders. Recently, invasive plant species have been identified as those able to successfully colonize diverse and heterogeneous regions. Phenotypic plasticity as a response to environmental variation is thought to aid invasion success. Thus, our study attempted to address the character variation in the form of extrafloral nectary (EFN) size and abundance and leaf area of the exotic plant Ricinus communis ( Euphorbiaceae ) across geography. In addition, we assessed the amount of herbivory on each plant sampled. R. communis individuals were sampled in Costa Rica and California across a total of eight habitat types. We found that plants in Costa Rica had larger leaves, smaller EFNs and fewer EFNs.There was no difference in herbivory levels between the two locations. Within-location R. communis individuals did exhibit plasticity across certain habitats. This study demonstrates that R. communis is a highly plastic species and characteristic of invasive plant species.