Lemna trisulca L.

ivy-leaved duckweed

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

The leaf-like blade in ivy-leaved duckweed is called a thallus. Longer and narrower than common duckweed (Lemna minor), the two species are often found together scattered among emergent plants or matted together in floating mats in mesotrophic or eutrophic lakes and rivers. This species is absent from most of interior northern New England, except for Vermont's Lake Champlain Valley.

Habitat

Lacustrine (in lakes or ponds), riverine (in rivers or streams)

Characteristics

Habitat
aquatic
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Roots
there is approximately one root per thallus
Thallus shape in cross-section
the thallus is somewhat flattened on at least one side in cross-section
Thallus length
3–15 mm
Thallus shape
the thallus is ovate (egg-shaped)
Thallus dimensions
2–3.5
Veins on upper surface
1–3
Show All Characteristics
  • Flowers
    Scale surrounding flower
    yes
    Stamen number
    2
  • Fruits or seeds
    Fruit length
    0.6–0.9 mm
    Seed surface ribbed
    the seed surface has ribs running from end to end
  • Growth form
    Root length
    0–25 mm
    Root number
    1
    Root sheath winged at base
    no
    Roots
    there is approximately one root per thallus
    Roots perforating basal scale
    there is no basal scale on the plant
    Thallus dimensions
    2–3.5
    Thallus edge
    the edge of the thallus has tiny teeth near the tip
    Thallus length
    3–15 mm
    Thallus shape
    the thallus is ovate (egg-shaped)
    Thallus shape in cross-section
    the thallus is somewhat flattened on at least one side in cross-section
    Thallus stalks
    the thallus has a stalk
    Thallus width
    0.9–7.5 mm
    Thallus with red pigment
    yes
    Turions
    no
  • Leaves
    Papilla on thallus
    no
    Veins on upper surface
    1–3
  • Place
    Habitat
    aquatic
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • in lakes or ponds
    • in rivers or streams

Wetland Status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England Distribution and Conservation Status

Distribution

Connecticut
present
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
present

Conservation Status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
fairly widespread (uncertain) (S-rank: S4?)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)

Native to North America?

Yes

Family

Araceae

Genus

Lemna

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Information from Dichotomous Key of Flora Novae Angliae

4.  Lemna trisulca L. N

ivy-leaved duckweed. CT, MA, ME, NH, RI, VT; extending north in the Lake Champlain Valley but not found in a large portion of the interior of northern New England. Circumneutral, mesotrophic to eutrophic waters of lakes and rivers.