Landoltia punctata — spotted-duck-meal
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Facts
Spotted-duck-meal is a non-native member of the duckweed family that reaches the northern edge of its range in Massachusetts. This tiny aquatic plant has "leaves" (thalli) with 5-7 veins, and about 2-7 dangling roots, all of which puncture the tiny scale at the base of the leaves. It inhabits high-nutrient waters of lakes and rivers.
Habitat
Lacustrine (in lakes or ponds), riverine (in rivers or streams)
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
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enlargeCharacteristics
- Habitat
- aquatic
- New England state
- Massachusetts
- Roots
- there are two or more roots per thallus
- Thallus shape in cross-section
- the thallus is somewhat flattened on at least one side in cross-section
- Thallus length
- 1.5–8 mm
- Thallus shape
- the thallus is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
- Thallus dimensions
- 1.5–2
- Veins on upper surface
- 3–7
-
Flowers
- Scale surrounding flower
- yes
- Stamen number
- 2
-
Fruits or seeds
- Fruit length
- 0.8–1 mm
- Seed surface ribbed
- the seed surface has ribs running from end to end
-
Growth form
- Root length
- Up to 70 mm
- Root number
- 1–12
- Roots
- there are two or more roots per thallus
- Roots perforating basal scale
- all the roots protrude through the basal scale
- Thallus dimensions
- 1.5–2
- Thallus edge
- the edge of the thallus is smooth (without teeth) near the tip
- Thallus length
- 1.5–8 mm
- Thallus shape
- the thallus is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
- Thallus shape in cross-section
- the thallus is somewhat flattened on at least one side in cross-section
- Thallus with red pigment
- yes
- Turions
- no
-
Leaves
- Papilla on thallus
- no
- Veins on upper surface
- 3–7
-
Place
- Habitat
- aquatic
- New England state
- Massachusetts
- Specific habitat
-
- in lakes or ponds
- in rivers or streams
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- absent
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- not applicable (S-rank: SNA)
From Flora Novae Angliae dichotomous key
1. Landoltia punctata (G.F.W. Mey.) Les & D.J. Crawford E
spotted-duck-meal. Lemna punctata G.F.W. Mey.; Spirodela punctata (G.F.W. Mey.) C.H. Thompson • MA. Mesotrophic to eutrophic waters of lakes and rivers.
Native to North America?
No
Sometimes confused with
- Spirodela polyrrhiza:
- thalli with mostly 7–16 veins, 1–1.5 times as long as wide, and roots numbering 7–21 per thallus, only 1 or 2 perforating the small, membranous scale at thallus base (vs. L. punctata, with thalli with mostly 5–7 veins, 1.5–2 times as long as wide, and roots numbering mostly 2–7, all perforating the small, membranous scale at thallus base).
Synonyms
- Lemna punctata G.F.W. Mey.
- Spirodela punctata (G.F.W. Mey.) C.H. Thompson