BugwoodWiki Article

Brazilian waterweed
Egeria densa Planch.

Overview

Appearance
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.
Foliage
The finely serrated leaves are usually less than 1 in. (2.5 cm) long and occur in whorls of 3-6.
Flowers
The flowers, which bloom above the surface of the water, are white with three petals.
Fruit
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.

Resources

Selected Images


1354041
1354041

Brazilian waterweed
Egeria densa
Foliage
Virginia Tech Weed Identification Guide Archive
5270021
5270021

Brazilian waterweed
Egeria densa
Flower(s)
Leslie J. Mehrhoff
5270022
5270022

Brazilian waterweed
Egeria densa
Foliage
Leslie J. Mehrhoff
5270023
5270023

Brazilian waterweed
Egeria densa
Foliage
Leslie J. Mehrhoff
5349039
5349039

Brazilian waterweed
Egeria densa
Infestation
William T. Haller
5396708
5396708

Brazilian waterweed
Egeria densa
Structure
Robert Vidéki
5447179
5447179

Brazilian waterweed
Egeria densa
Flower(s)
Leslie J. Mehrhoff
5447183
5447183

Brazilian waterweed
Egeria densa
Flower(s)
Leslie J. Mehrhoff
5400389
5400389

Brazilian waterweed
Egeria densa
Plant(s)
Graves Lovell
5349040
5349040

Brazilian waterweed
Egeria densa
Feature(s)
Ann Murray

Maps


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

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

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.

State Regulated List
Legend
   No Data for this state
   Troublesome or Common weed in one or more crops

Invasive Listing Sources

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Alismatidae
Order: Hydrocharitales
Family: Hydrocharitaceae
Genus: Egeria

Other System Links

Plants: EGDE
Bayer: ELDDE
GRIN: 400175
ITIS: 38972
NPDN Pest: PCHAGBA

Synonyms and Other Names

Other Common Names:
Brazilian waterweed, Brazilian elodea, South American waterweed

Related Scientific Names:

Anacharis densa (Planch.) Victorin(Synonym)
Elodea densa (Planch.) Caspary(Synonym)
Philotria densa (Synonym)

Categories

Category: Aquatic