CHARACTERIZING THE INVASIVE POTENTIAL OF ORNAMENTAL PLANTS

Abstract

The substantial economic and ecological costs of invasive plant management and removal warrant aggressive eradication and prevention programs. Ornamental horticulture has been recognized as the fastest growing segment of U.S. Agriculture, as well as the main source of plant invasions worldwide. Florida ranks second among U.S. states in the degree of ecosystem devastation as a result of exotic invasive species. Cultivated or improved forms of a number of the ornamental species listed as invasive by Florida’s Exotic Pest Plant Council have been selected for their attractive flower color, plant form, foliage, drought tolerance, or cold hardiness. As the cultivars are generally propagated vegetatively, relatively little is known about their pollination biology, seed production, seed viability and growth rate under varying conditions. To identify safe alternatives to ornamental invasives, researchers at the University of Florida have evaluated numerous cultivars of Mexican petunia (Ruellia tweediana), privet (Ligustrum spp.), fountain grass (Pennisetum spp.), porterweed (Stachytarpheta spp.), heavenly bamboo (Nandina domestica), and lantana (Lantana camara). These species are not only problematic in Florida, but highly invasive in other parts of the world. Research efforts are underway to identify and evaluate sterile non-invasive forms of lantana, heavenly bamboo, and Mexican petunia.