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A dense mat near the surface of the water of a long thing plant with small leaves attached to a thin stem.

Other names: Hydrilla, Florida elodea, water thyme, Indian star-vine, Hydrilla verticillata

Where did it come from?

Hydrilla was introduced from the Eastern Hemisphere in the 1960s. It was brought into Florida for use in the aquarium trade.

Why is it invasive?

Large mats of hydrilla out compete native plants, tangle propellers, slow hydroelectric power production, and make other water activities difficult. When hydrilla dies, decomposition of dead hydrilla depletes oxygen, killing aquatic animals and plants.

How do you prevent its spread?

Clean, drain, and dry equipment and boats before moving to a new body of water.


♦ Spotlight: Hydrilla

♦ Hydrilla fact sheet

Seen it? Report it! Through the app, online, by email, or by phone (1-866-663-9684).

Image credit: David J. Moorhead, University of Georgia, Bugwood.org