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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.
Description:
| 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 |
Habitat:
- 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.
Impact:
- 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.
Look-alikes:
Leafy elodea is often confused with native waterweed (Elodea canadensis). Waterweed’s leaves are smaller and grow in whorls of three.
Noxious Weed Listing:
| State of Oregon: | Class B |
| State of Washington: | Class B |
More Resources:
For more detailed information, download the Leafy Elodea Best Management Practices factsheet
- University of California, Weed Research & Information Center: Brazilian egeria