Leafy elodea. Photo Credit: Graves Lovell, Alabama Department of Conservation and Natural Resources, Bugwood.org
Leafy elodea. Photo Credit: Robert Vidéki, Doronicum Kft., Bugwood.org
Leafy elodea flowers. Photo credit: Hörður Kristinsson, Flickr.
Photo Credit: US Geological Survey
Comparison of leafy elodea and waterweed. Photo Credit: Robert Vidéki, Doronicum Kft., Bugwood.org
Also known as: Brazilian elodea, Brazilian waterweed, South American waterweed, dense waterweed
Leafy elodea is an ornamental freshwater plant that is often used in fish aquariums. Once in a natural waterbody, it forms dense mats which alter aquatic ecosystems, restrict water flow, and water recreation.
|Life Cycle:||Perennial (life cycle lasts more than one year)|
|Early Detection and Rapid Response species:||Yes|
|Height:||Submerged stems can grow up to 6 feet (2 meters) long.|
|Leaf Description:||Bright green leaves grow in whorlsWhorls An arrangement of leaves that radiate from a single point and wrap around the plant’s stem. of four to six. Leaves are more robust at the end of the stem, giving it a bottlebrush appearance. They have small serrations on their edges that require a magnifying glass to observe.|
|Flower Description:||White, three petaled flowers have yellow centers. The flowers float on the water’s surface.|
|Bloom Time:||June to August|
- Leafy elodea grows in still or slow-moving water such as lakes, ponds, and streams.
- It is usually rooted to the bottom of waterbodies but can also be free-floating.
- Leafy elodea spreads by plant fragments. Its dense mats alter aquatic ecosystems and restrict water flow.
- These mats also hinder water recreation like fishing, swimming, and boating.
- Removing leafy elodea costs millions of dollars per year and it can take several years to eradicate.
What we’re doing about it:
- Leafy elodea is a priority species for the Tualatin SWCD. As such, our Invasive Species Program has been actively monitoring and treating it throughout the watershed.
- If identified within Washington County, a specially trained crew can come out and survey for it. If found, the crew will treat the infestation for free.
What you can do about it:
- Please report any leafy elodea infestations to the Oregon Invasive Species Hotline.
- Prevention is the best control. If you have any unwanted aquarium plant material, dispose of it in a tied plastic bag in the garbage.
- If you are recreating in natural waterbodies make sure any equipment such as boats, kayaks, or canoes is cleaned, drained, and dried before entering or leaving an area.
- Careful mechanical removal by hand pulling or netting is feasible for small infestations. Repeated removal will be necessary since leafy elodea spreads by plant fragments.
Leafy elodea is often confused with native waterweed (Elodea canadensis). Waterweed’s leaves are smaller and grow in whorls of three.
Noxious Weed Listing:
For more detailed information, download the Leafy Elodea Best Management Practices factsheet
- University of California, Weed Research & Information Center: Brazilian egeria