Water Hyacinth

The seven species of water hyacinths comprise the genus Eichhornia of free-floating perennial aquatic plants native to tropical South America. With broad, thick and glossy ovate leaves, water hyacinths may raise some one meter in height. The leaves are 10-20 cm across, supported above the water surface by long, spongy and bulbous stalks. The feathery, freely hanging roots are purplish black. An erect stalk supports a single spike of 8-15 conspicuously attractive flowers, mostly lavender to pinkish in color with six petals. When not in bloom, water hyacinth may be mistaken for frog's-bit (Limnobium spongia).

One of the fastest growing plants known, water hyacinth reproduces primarily by way of runners or stolons, eventually forming daughter plants. They may also reproduce via seeds. The common water hyacinth (Eichhornia crassipes) is a vigorous grower known to double its population in two weeks.

Water Hyacinths have been widely introduced throughout North America, Asia, Australia and Africa. They can mainly be found in Louisiana large water areas. In many areas they, particularly Eichhornia crassipes, are important and pernicious invasive species. First introduced to North America in 1884, an estimated 50 kilograms per square meter of hyacinth once choked Florida's waterways, although the problem there has since been mitigated.

When not controlled, water hyacinth will cover lakes and ponds entirely; this dramatically impacts water flow, blocks sunlight from reaching native aquatic plants, and starves the water of oxygen.