Potential allelopathic effects of Brazilian pepper (Schinus terebinthifolius Raddi, Anacardiaceae) aqueous extract on germination and growth of selected Florida native plants1

Morgan, E.C., and W.A. Overholt (University of Florida Indian River Research and Education Center, 2199 So. Rock Rd., Ft. Pierce FL 34949). Potential allelopathic effects of Brazilian pepper (Schinus terebinthifolius Raddi, Anacardiaceae) aqueous extracts upon germination and growth of selected Florida native plants. J. Torr. Bot. Soc. 132: 11–15. 2005.—Schinus terebinthifolius, or Brazilian pepper, is an exotic invasive plant found throughout much of peninsular Florida. It rapidly colonizes disturbed areas, often forming dense monotypic stands, and displaces native vegetation. In the current study we examined a potential mechanism by which Brazilian pepper has become a major invader of Florida's ecosystems. In laboratory bioassays and greenhouse experiments, germination and biomass accumulation in two native Florida plant species, Bidens alba and Rivina humilis, were negatively affected by irrigation with aqueous extracts of Brazilian pepper leaves. This study illustrates a potential mechanism through which one plant may gain a competitive advantage over another.