Wolffia borealis(Engelm.) Landolt

northern watermeal

WFO wfo-0000334451 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Wolffia borealis, photographed by Renato Robert
fig. a Renato Robert, CC BY 4.0 / 2020-09-12 / obs. 94861201
Wolffia borealis, photographed by Reuven Martin
fig. b Reuven Martin, CC0 1.0 / obs. 86403389
Wolffia borealis, photographed by Kenneth Burdick
fig. c Kenneth Burdick, CC BY 4.0 / obs. 47491408
Wolffia borealis, photographed by Quinten Wiegersma
fig. d Quinten Wiegersma, CC BY 4.0 / obs. 45718859
Wolffia borealis, photographed by Dan MacNeal
fig. e Dan MacNeal, CC BY 4.0 / obs. 23093831
Wolffia borealis, photographed by Jared Shorma
fig. f Jared Shorma, CC BY 4.0 / obs. 199714123
Wolffia borealis, photographed by Jenn (McPhee) Dyson
fig. g Jenn (McPhee) Dyson, CC BY 4.0 / obs. 43866092
Wolffia borealis, photographed by Derek
fig. h Derek, CC BY 4.0 / obs. 40481580

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 28 botanical countries

Regions where Wolffia borealis is native: Alberta, British Columbia, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New York, Ontario, Oregon, Pennsylvania, Québec, South Dakota, Tennessee, Utah, Vermont, Virginia, Wisconsin AlbertaBritish ColumbiaCaliforniaColoradoConnecticutIdahoIllinoisIndianaIowaKansasKentuckyMassachusettsMichiganMinnesotaMissouriNebraskaNew HampshireNew YorkOntarioOregonPennsylvaniaQuébecSouth DakotaTennesseeUtahVermontVirginiaWisconsin
Native distribution of Wolffia borealis, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Alberta ABT NORTHERN AMERICA
British Columbia BRC
California CAL
Colorado COL
Connecticut CNT
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Massachusetts MAS
Michigan MIC
Minnesota MIN
Missouri MSO
Nebraska NEB
New Hampshire NWH
New York NWY
Ontario ONT
Oregon ORE
Pennsylvania PEN
Québec QUE
South Dakota SDA
Tennessee TEN
Utah UTA
Vermont VER
Virginia VRG
Wisconsin WIS

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Also published as 1 synonym

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Wolffia brasiliensis var. borealis Engelm.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.