common water hyacinth

Eichhornia crassipes (Mart.) Solms

U.S. Nativity: Exotic
Habit: Aquatic

Synonym(s): floating water hyacinth

Eichhornia crassipes is a free floating aquatic plant that has invaded aquatic areas throughout the eastern and southern portions of the United States. Plants can grow to 3 ft. (1 m) in height.
The leaves are oval to elliptical, thick, up to 6 in. (15 cm) wide and waxy with spongy petioles. Leaves curve inward at the edges.
The very showy blue-purple flowers are born on upright spikes. Each flower has six petals with the uppermost having a yellow patch.
This plant reproduces chiefly by vegetative means.
Ecological Threat
Eichhornia crassipes invades lakes, ponds, rivers, marshes, and other types of wetland habitats. It can quickly form dense floating mats of vegetation (populations can double in size in two weeks!). These dense mats restrict light to the underwater environment, reduce the light availability for submersed plants and aquatic invertebrates, and deplete the oxygen levels. Eichhornia crassipes is native to South America and was first introduced as an ornamental into the United States in 1884 at the Cotton States Exposition in New Orleans.

Identification, Biology, Control and Management Resources

Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service
Southeast Exotic Pest Plant Council Invasive Plant Manual - SE-EPPC
Element Stewardship Abstract - The Nature Conservancy
Identification and Biology of Non-Native Plants in Florida's Natural Areas - University of Florida
Global Invasive Species Database - Invasive Species Specialist Group