The plant Salvinia molesta , generally known as Giant Salvinia or Kariba weed, is a free floating pterophyta indigenous to south-east brazil (Julien et. al 1987). Today plants and animals are shipped, sometimes accidentally, all over the globe to zoos, botanical gardens, and for commercial and agricultural purposes. A small minority of "alien" plants, or introduced, species become ecological as well as economic disasters. Although they may have been innocuous in their native region, these species are transformed into aggressive pests or weeds that invade and dominate their new environment (Barrett 1989) Nowhere are these biological invasions more evident than in the rivers lakes and reservoirs of the world. Giant Salvinia, one of the worst aquatic weeds in the world, exemplifies this problem. It is notorious for it's ability to colonize large areas of water in a short space of time. The explosive growth of these plants has caused difficulties in North America, Africa, Asia, and Australia
             Salvinia is a sterile floating fern native to South America (Julien et. al 1987). The basic morphological module of Salvinia is a ramet, each of which consist of a segment of rhizome bearing three distal leaves and , initially, an apical bud and a lateral bud which both have the potential to grow new ramets (Room 1988). True roots are absent and a one of the leaves is modified and hangs down into the water functioning as a root (Julien 1988). During early stages plants are smaller and leaves lie flat on the water surface. As plants grow, leaves curl at the edges in response to self competition (Jacono 2000). Mature plants can produce large quantities of sporocarps that contain many sporangia, yet plants are functionally sterile. Spores, only rarely found, are deformed and infertile, the result of improper chromosome pairing in this pentaploid species (Mitchell and Thomas 1972). As the oldest ramet in a colony becomes s...