Brazilian Elodea (Egeria densa) (also called Brazilian Waterweed, Anacharis)

Description:

Brazilian elodea
Brazilian elodea - photo from WI DNR

Appearance: Submersed aquatic plant. Perennial. Can be rooted or free floating.

Leaves: Bushy appearance. Leaves in whorls of 4 to 6. Leaf edges have very small serrations that require a magnifying glass to see.

Flowers: White flowers with 3 petals are on short stalks and are visible above water. Flowers are 0.7 to 1 inch wide.

Reproduction: Spreads by plant fragments. No female plants have been reported in the United States. Since all plants are male, no seeds are produced in the US. 

Note on identification: Brazilian elodea can be easily confused with native Canada waterweed.

  • Brazilian elodea usually has four leaves per whorl (arranged around the stem) and each leaf is at least 2 cm long.
  • Canada waterweed generally has three leaves per whorl and each leaf is usually less than 1 cm long.

See the reporting invasive aquatic plants webpage if you are unsure of identification or wish to report a new location of Brazilian elodea.

Ecological Threat:

  • Brazilian elodea is native to South America and was introduced to the United States as part of the aquarium trade. Never release aquarium plants and animals into the wild.
  • Brazilian elodea can form dense mats that outcompete native species and can interfere with recreational activities such as boating, swimming, and fishing.
  • Brazilian elodea is a regulated invasive species in Minnesota

 

Control Methods:

Prevention: Brazilian elodea is reported in very few lakes in Minnesota (see infested waters list). By cleaning all plant parts off of boats and water-related equipment, we can prevent the spread of Brazilian elodea to additional lakes.

Mechanical or chemical: See DNR regulations for submersed aquatic plant management strategies and regulations. 

Additional resources: