- Egeria densa is a submersed aquatic plant that invades freshwater systems throughout much of the United States. Often confused with hydrilla, Egeria densa has a smooth midrib on the underside of the leaf, whereas hydrilla has small teeth.
- The finely serrated leaves are usually less than 1 in. (2.5 cm) long and occur in whorls of 3-6.
- The flowers, which bloom above the surface of the water, are white with three petals.
- Outside of its native habitat, Egeria densa only reproduces vegetatively. Special double nodal regions can produce lateral buds, branches and roots. Only a double node can produce a new plant when it breaks off from the parent plant.
- Ecological Threat
- Egeria densa invades both still and flowing water ecosystems including lakes, ponds, ditches, and rivers. It can form dense stands that crowd out native vegetation and reduce the area's value as fish habitat. It can also interfere with recreational activities such as fishing and swimming. This plant was first introduced into the United States in the late 1800s as an aquarium plant.
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EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Invasive List - This map identifies those states that list this species on their invasive species list. For more information, visit Invasive.org
Most Troublesome / Most Common Agricultural Weed List
This map identifies those states that consider this species either most troublesome or most common in at least one commodity. For more information, visit the MTMC project page.
|No Data for this state|
|Troublesome or Common weed in one or more crops|
Invasive Listing Sources
- Alabama Noxious Weeds - Class C Noxious Weed
- Apalachicola Invasive Working Group
- California Invasive Plant Council
- California Noxious Weeds
- Colorado Noxious Weeds
- Connecticut Invasive Plant List
- Connecticut Invasive Plant Working Group
- Delaware Natural Resources and Environmental Control, 2004
- East Central Florida CISMA
- EDDMapS Ontario
- Faith Campbell, 1998
- Georgia Exotic Pest Plant Council - Category 2
- Idaho Noxious Weeds
- Illinois Invasive Plant List
- Indiana Noxious Weeds
- Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
- John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
- Maine Noxious Weeds
- Massachusetts Noxious Weeds
- Mid-Atlantic Exotic Pest Plant Council, 2005
- Native Plant Society of Oregon, 2008
- New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture, Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
- New Hampshire Prohibited Aquatic Species
- Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
- Oregon Noxious Weeds
- South Carolina Noxious Weeds
- Tennessee Exotic Pest Plant Council
- Vermont Department of Environmental Conservation
- Vermont Noxious Weeds
- Virginia Invasive Plant Species List
- Washington Noxious Weeds
- WeedUS - Database of Plants Invading Natural Areas in the United States
- Wisconsin's Invasive Species Identification, Classification and Control Rule
|Common Name Reference:|| USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.|
|Scientific Name Reference:||USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.|