Brazilian ElodeaEgeria densa

Darren R. ThornhillFisheries Management Biologist

MO Dept. of Conservation3500 S Baltimore St.Kirksville, MO 63501

What does it look like?

• Submerged, perennial plant

• Stems (up to 2 m) branch at water level

• Whorls of 4-8 spear-shaped leaves (1.2-3.8 cm)

• Three white flowers (18-25 mm) at or just above water surface

Ecology

• All known plants in the US are male– Spreads through fragmentation

• Found in still and moving water

• Found in depths ranging up to 7 meters– Also found in free-floating mats

• Develops dense, monotypic stands

How did it get here?

• Native of Brazil and coastal Argentina and Uruguay

• First collected in Long Island, NY in 1893– First sold in US in 1915 as good “oxegenator”

• Commonly cultivated and sold for the aquarium trade– Anacharis

How do we get rid of it?

• Prevention is paramount!

• Biological control with grass carp

• Mechanical control is not recommended

• Chemical control is effective

– Complexed copper and diquat (effective)

– Complezed copper and Endothall (marginally effective)

– Fluridone (effective)