Lemna valdiviana Phillipi

pale duckweed

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

New England Distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America Distribution

Adapted from BONAP data

enlarge

Facts About

Although Pale duckweed is a widespread native species found in several New England states, it is considered endangered in New Hampshire. The "leaves" (thalli) of this aquatic plant have a prominent midvein that extends nearly the length of the leaf, and their bases are asymmetrical.

Habitat

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

Characteristics

Habitat
aquatic
New England state
  • Connecticut
  • Massachusetts
  • New Hampshire
  • Rhode Island
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
1–5 mm
Thallus shape
  • the thallus is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the thallus is ovate (egg-shaped)
Thallus dimensions
1.3–3
Veins on upper surface
1
Show All Characteristics
  • Flowers
    Scale surrounding flower
    no
    Stamen number
    2
  • Fruits or seeds
    Fruit length
    1–1.35 mm
    Seed surface ribbed
    the seed surface has ribs running from end to end
  • Growth form
    Root length
    Up to 15 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
    1.3–3
    Thallus edge
    the edge of the thallus is smooth (without teeth) near the tip
    Thallus length
    1–5 mm
    Thallus shape
    • the thallus is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • 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 with red pigment
    no
    Turions
    no
  • Leaves
    Papilla on thallus
    • no
    • yes
    Veins on upper surface
    1
  • Place
    Habitat
    aquatic
    New England state
    • Connecticut
    • Massachusetts
    • New Hampshire
    • Rhode Island
    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
absent
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
absent

Conservation Status

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

Connecticut
unrankable (S-rank: SU)
Massachusetts
historical (S-rank: SH), H (code: H)
New Hampshire
historical (S-rank: SH), endangered (code: E)
Rhode Island
extremely rare (S-rank: S1), concern (uncertain) (code: C*)

Native to North America?

Yes

Sometimes Confused With

Lemna minuta:
vein usually not extending past aerenchyma tissue, extending less than 2/3 of distance from root node to tip of thallus, thalli mostly 1–2.5 mm long, 1–2 times as long as broad, broad-elliptic to broad-oblong or obovate (vs. L. valdiviana, with the vein usually extending past aerenchyma tissue, extending at least 3/4 of the distance from the root node to the tip of the thallus, and thalli 2–4 mm long, 1.3–3 times as long as wide, elliptic to lanceolate or obovate).

Synonyms

  • Lemna torreyi Austin

Family

Araceae

Genus

Lemna

Need Help?

Get Help

Information from Dichotomous Key of Flora Novae Angliae

6.  Lemna valdiviana Phil. NC

pale duckweed. Lemna torreyi Austin • CT, MA, NH, RI. Mesotrophic to eutrophic waters of 
lakes, rivers, beaver flowages, and pools.