Wolffia brasiliensis — Brazilian water-meal
![Thalli: Wolffia brasiliensis. ~ By Gordon Morrison. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Araceae/wolffia-brasiliensis-ta-gmorrison.jpg)
![Flowers and fruits: Wolffia brasiliensis. ~ By Gerry Carr. ~ Copyright © 2024 Gerry Carr. ~ gdcarr[at]comcast.net ~ U. of Washington - WTU - Herbarium - biology.burke.washington.edu/herbarium/imagecollection.php](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Araceae/wolffia-brasiliensis-ff-gcarr2.jpg)
![Plant form: Wolffia brasiliensis. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Araceae/wolffia-brasiliensis-ha-ahaines.jpg)
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Facts
Wolffia brasiliensis is a floating, rootless, aquatic plant that is native to North and South America.
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.
Found this plant? Take a photo and post a sighting.
enlargeCharacteristics
- Habitat
- aquatic
- New England state
-
- Connecticut
- Maine
- Massachusetts
- Rhode Island
- Roots
- there are no roots on the plant
- Thallus shape in cross-section
- the thallus is somewhat flattened on at least one side in cross-section
- Thallus length
- 0.5–1.6 mm
- Thallus shape
-
- the thallus is elliptic (widest near the middle and tapering at both ends)
- the thallus is oblong (rectangular but with rounded ends)
- the thallus is ovate (egg-shaped)
- Thallus dimensions
- 1–1.5
- Veins on upper surface
- 0
-
Flowers
- Scale surrounding flower
- no
- Stamen number
- 1
-
Fruits or seeds
- Seed surface ribbed
- the seed surface is nearly smooth
-
Growth form
- Root length
- 0 mm
- Root number
- 0
- Root sheath winged at base
- NA
- Roots
- there are no roots on the plant
- Roots perforating basal scale
- NA
- Thallus dimensions
- 1–1.5
- Thallus edge
- the edge of the thallus is smooth (without teeth) near the tip
- Thallus length
- 0.5–1.6 mm
- Thallus shape
-
- the thallus is elliptic (widest near the middle and tapering at both ends)
- the thallus is oblong (rectangular but with rounded 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 does not have a stalk
- Thallus width
- 0.2–0.5 mm
- Thallus with red pigment
- no
- Turions
- yes
-
Leaves
- Papilla on thallus
- yes
- Veins on upper surface
- 0
-
Place
- Habitat
- aquatic
- New England state
-
- Connecticut
- Maine
- Massachusetts
- Rhode Island
- 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
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- absent
- 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)
- Maine
- unrankable (S-rank: SU), special concern (code: SC)
- Massachusetts
- fairly widespread (S-rank: S4)
From Flora Novae Angliae dichotomous key
2. Wolffia brasiliensis Weddell N
Brazilian water-meal. Bruniera punctata (Griseb.) Nieuwl.; Wolffia papulifera C.H. Thompson; W. punctata Griseb. • CT, MA, ME, RI. Mesotrophic to eutrophic waters of lakes, rivers, and backwaters.
Native to North America?
Yes
Sometimes confused with
- Wolffia borealis:
- thalli with a minute, upward-bent point at each apex, lacking a central papilla, 1.3–2 times as long as wide (vs. W. brasiliensis, with thalli rounded at each apex, with a large, prominent papilla in the center of the upper surface, 1–1.5 times as long as wide).
Synonyms
- Bruniera punctata (Griseb.) Nieuwl.
- Wolffia papulifera C.H. Thompson
- Wolffia punctata Griseb.