Wolffia columbiana — Columbian water-meal
![Plant form: Wolffia columbiana. ~ By Andrew Nelson. ~ Copyright © 2024 Andrew Nelson. ~ andrew.nelson[at]oswego.edu ~ Flora of Rice Creek Field Station - www.oswego.edu/academics/opportunities/rice_creek_field_station](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Araceae/wolffia-columbiana-ha-anelson2.jpg)
![Roots: Wolffia columbiana. ~ By Julian A. Steyermark. ~ Copyright © 2024. ~ Allison Brock, Allison.Brock[at]mobot.org ~ Steyermark, Julian A. 1963. The Flora of Missouri. The Iowa State U. Press, Ames, IA. 1725pp.](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Araceae/wolffia-columbiana-ro-jsteyermark1.jpg)
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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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enlargeFacts
Columbian water-meal is generally considered to be the smallest flowering plant on earth, less than 1/16 inch (1.5 mm) long. It floats at the water surface in mesotrophic to eutrophic lakes, rivers and backwaters. It is widely distributed across North, Central and South America. But it is rare and sporadic in northern New England.
Habitat
Lacustrine (in lakes or ponds), riverine (in rivers or streams)
Characteristics
- Habitat
- aquatic
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Roots
- there are no roots on the plant
- Thallus shape in cross-section
- the thallus is rounded in cross-section
- Thallus length
- 0.5–1.4 mm
- Thallus shape
- the thallus is orbicular (roughly circular, as wide as long)
- Thallus dimensions
- 1–1.3
- 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
- 1–1.3
- Thallus edge
- the edge of the thallus is smooth (without teeth) near the tip
- Thallus length
- 0.5–1.4 mm
- Thallus shape
- the thallus is orbicular (roughly circular, as wide as long)
- Thallus shape in cross-section
- the thallus is rounded in cross-section
- Thallus stalks
- the thallus does not have a stalk
- Thallus width
- 0.4–1.2 mm
- Thallus with red pigment
- no
- Turions
- yes
-
Leaves
- Papilla on thallus
- no
- Veins on upper surface
- 0
-
Place
- Habitat
- aquatic
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- 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.
- Maine
- rare (S-rank: S2), special concern (code: SC)
- Massachusetts
- unranked (S-rank: SNR)
Native to North America?
Yes
Sometimes confused with
- Wolffia borealis:
- plants flattened on top and with an upward bent point at each end (vs. W. columbiana, which are plants spherical to ovoid, not flattened on the upper surface, without any upward bent points).
Synonyms
- Bruniera columbiana (Karst.) Nieuwl.
Family
Genus
From the dichotomous key of Flora Novae Angliae
3. Wolffia columbiana Karst. N
Columbian water-meal. Bruniera columbiana (Karst.) Nieuwl. • CT, MA, ME, NH, VT; rare and sporadic in northern New England. Mesotrophic to eutrophic waters of lakes, rivers, and backwaters.