Introduction

Cabomba (Cabomba caroliniana Gray, Cabombaceae), or water fanwort, is a fast-growing submerged aquatic plant that has the potential to infest permanent water bodies in a range of regions – from tropical to cool temperate – throughout the world. It is considered a serious pest in the United States, Canada, the Netherlands, Japan, India, China, and Australia, and is present in Hungary, South Africa, and the United Kingdom. Cabomba grows well in slow-moving water bodies, preferring areas of permanent standing water less than 4 m deep; however, it can also grow at depths up to 6 m in Australia (Schooler and Julien, 2006). The weed is recognized by its opposing pairs of finely dissected underwater leaves that are feathery or fan-like in appearance (Fig. 6.1 and Fig. 6.2). Small white flowers bearing three petals and three sepals extend above the water surface, making infestations more visible in summer months. Reproduction is almost entirely vegetative throughout most of the introduced localities and any fragment that includes nodes can grow into a new plant (Sanders, 1979).

Cabomba originates from South America (Orgaard, 1991). The plant's tolerance of fragmentation and delicate appearance make it a desirable aquarium plant (Hiscock, 2003) and consequently it was brought into many countries through the aquarium trade. Cabomba was subsequently introduced into lakes and streams both accidentally, through the dumping of aquarium water, and on purpose, to enable cultivation for later collection and sale.