anchored waterhyacinth
Eichhornia azurea (Swartz) Kunth

Overview

Appearance

Eichhornia azurea is a rooted perennial aquatic plant. It has long stems which grow to reach the surface of the water. It is native to parts of Central and South America.

Foliage

Leaves are alternate along the stem. Submersed leaves are sessile while emersed leaves are petiolate. The petiole is never inflated as with Eichhornia crassipes.

Flowers

Flowers are held on erect stems above the surface of the water. There can be from 7 to as many as 50 flowers per stem. Each flower blooms for only a day. Flowering can occur from summer through fall.

Fruit

Each flower can produce 10 to 13 small winged seeds.

Ecological Threat

Eichhornia azurea grows rapidly and can very quickly form expansive mats of floating plants, completely covering even large lakes. This complete coverage of the surface of the water blocks sunlight and depletes the oxygen available to the rest of the aquatic community. It can make the body of water uninhabitable by other aquatic organisms. Eichhornia azurea is listed as a noxious weed in the United States. It has only been reported in Florida.

Resources

• Federal Noxious Weed Disseminules of the U.S. - USDA-APHIS
• Flora of North America -

Selected Images

Maps

Invasive Listing Sources

• Federal Noxious Weeds
• Indiana Invasive Species Council - Invasive Plant List
• Indiana Pest Species
• Indiana Prohibited Plant Species
• Maryland Department of Natural Resources Policy: Restriction on Planting Exotic Invasive Plants
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• South Carolina Illegal Aquatic Plants
• Texas Noxious Weeds
• Treasure Coast Cooperative Invasive Species Mgmt. Area
• USDA APHIS Regulated Pest List
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References