Weed Information: Egeria densa (elodea, Brazilian)
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Egeria densa (elodea, Brazilian)

Family: Hydrocharitaceae

Description

Submerged aquatic plants, cylindrical in outline due to the dense leafy stems. Leaves 4 - 6 per whorl. No female plants of this species have been found in the U.S.; hence all reproduction is from vegetative fragments. Very similar in appearance to Hydrilla verticillata but with only minute teeth (or none) on the leaf margins, while those of Hydrilla are more prominent.

Characteristics

Flower Color
  • White
Inflorescence Type (How the flowers are arranged on the plant)
  • Axillary cluster
  • Solitary, axillary
Number of Petals
  • 3 petals
Petal Separation
  • Completely free to base
Petal Tip
  • Pointed
  • Rounded
  • Square
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
Flower Width (Head width in the Asteraceae)
  • 1.5 cm (.60 inch)
  • 2.0 cm (.80 inch)
  • 2.5 cm (1.0 inch)
Number of Sepals
  • 3 sepals
Sepal Separation
  • Completely free to base
Sepal Tip
  • Pointed
Flower Sex
  • Unisexual (monoecious or dioecious)
Number of Styles
  • Styles lacking (male flowers only)
Number of Stamens
  • 9 stamens
Stamens Attached to the Petals
  • Stamens NOT attached to the petals
Stamens Connate (united)
  • Filaments or anthers NOT united

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 0 (male flowers only or plants producing spores)
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Capsule, 1-celled
  • Capsule, 3-celled
Fruit Length at Maturity
  • 1 mm (.04 inch) or less
Fruit Width at Maturity
  • 1 mm (.04 inch) or less
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Whorled 4 per node
  • Whorled 5 - 8 per node
Leaf Type
  • Simple (including lobed leaves)
Stipules
  • Lacking
Tendrils
  • Tendrils absent
Petiole (leaf stem) Blade Ratio
  • Petiole absent (leaf sessile)
Leaf Length (blade PLUS petiole)
  • 2 - 4 cm (.80 - 1.60 inches)
Leaf Width
  • 1 - 5 mm (.04 - .20 inch)
Leaf Shape (simple leaves only)
  • Lanceolate
  • Linear or filiform
Leaf or Leaflet Margin
  • Entire
Leaf or Leaflet Blade Base
  • Acute (cuneate)
Leaf or Leaflet Tip
  • Acute
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
Succulence
  • Not succulent

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
Life Cycle
  • Annual
  • Perennial
Growth Habit (while flowering)
  • Erect, columnar (narrow)
  • Submerged (mostly or totally)
Plant Height at Maturity
  • 5 - 10 cm (2.0 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
  • 4 - 6 dm (1.3 - 2.0 feet)
  • 6 - 8 dm (2.0 - 2.6 feet)
  • 8 - 10 dm (2.6 - 3.3 feet)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Aquatic
Chlorophyll
  • Present

Stem Cross Section
  • Round
Flowering Stem Leaves
  • Stem uniformly leafy
Main Stem Branches
  • Main stem unbranched
  • Main stem branched

Root or Vegetative Propagule
  • Fibrous
  • Rooting at the nodes

US State
  • Alabama
  • Arkansas
  • Connecticut
  • Delaware
  • Florida
  • Georgia
  • Illinois
  • Kansas
  • Kentucky
  • Louisiana
  • Massachusetts
  • Missouri
  • Mississippi
  • North Carolina
  • New Hampshire
  • New Jersey
  • New York
  • Ohio
  • Pennsylvania
  • South Carolina
  • Tennessee
  • Texas
  • Virginia
  • West Virginia
  • Hawaii
  • Indiana
  • Maryland
  • Vermont
  • Arizona
  • California
  • Colorado
  • Idaho
  • New Mexico
  • Oklahoma
  • Oregon
  • Utah
  • Washington
  • Nebraska
Canadian Province or Territory
  • British Columbia
Other
  • Puerto Rico

  • Aquatic and Riparian Plants of the West, 2003 (ISBN# 1-879906-59-7) See page: 96
  • Common Weeds of the United States, 1971 (ISBN 0-486-20504-5) See page: 30
  • Gilkey`s Weeds of the Pacific Northwest, 1980 (ISBN 0-88246-039-0) See page: 25
  • Weeds of the South, University of Georgia 2009, ISBN#0-8203-3046-9 See page: 340
  • Weeds of the United States and Their Control, Lorenzi 1987, ISBN# 0-442-25884-4 See page: 47
  • Listed as a `Weed` by the Biota of North America Program, 2008 X
  • Listed in the WSSA Composite List of Weeds X
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