The water hyacinth is a beautiful pest that is best admired on a computer screen. Click to download a large version (800x600) of this image.

Description
Water hyacinth is a floating water plant with thick, shiny, spoon-shaped leaves originating from a basal rosette. The petioles (leaf stalks) are inflated and spongy, and keep the plant afloat. The feathery roots are purplish and hang down in thick masses that are 1 ft (0.3 m) long or even longer. The showy inflorescence is a 6 in (15.2 cm) spike that emerges from the center of the rosette with 5 to 20 purplish-blue or lavender flowers, each with yellow spots on the upper petals.

Location
Native to tropical America but escaped from cultivation and now naturalized in the southeastern US and warm areas throughout the world. Water hyacinth flourishes in ditches, canals, ponds and sluggish rivers.

CultureLight: Needs full sunlight.Moisture:Water hyacinth normally floats on the water's surface, but it can withstand periods of drawdown when it will root in the mud as long as it doesn't dry out completely. Hardiness: USDA Zones 8 - 11.Propagation: Increase by offshoots. (But don't do it!)

Usage
Where possession is not prohibited, water hyacinth is used in ornamental pools and aquaria where it provides excellent cover for fish and the invertebrates upon which they feed. Cut flowers are strikingly beautiful.

A blanket of water hyacinths is smothering this Florida lake.

Features
Water hyacinth was introduced from South America into Florida near Jacksonville in the 1880's and quickly became a million-dollar pest, completely choking waterways and shading out native aquatic plants. It has since been brought under "maintenance control", which means that with constant mechanical harvesting and application of herbicides, officials now are able to keep the weed at low, manageable, levels.

Water hyacinth has one of the fastest growth rates of any plant known. Populations can double in 12 days! It is a major pest weed in tropical and subtropical areas throughout the world. Water hyacinth can completely cover lakes and rivers with more than 200 tons per acre. It blocks boat traffic, shades out submerged plants, crowds out emergent plants, reduces oxygen in the water and reduces biological diversity.

WARNING
Water hyacinth is on the State of Florida's list of prohibited plants which means that it cannot be possessed, collected, transported, cultivated or imported without a permit from the Department of Environmental Protection.