Zannichellia palustrisL.

Horned PondweedHorned pondweedhorned pondweedhorned-pondweed

WFO wfo-0000770293 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Zannichellia palustris, photographed by Nicolás Lavandero
fig. a Nicolás Lavandero, CC BY 4.0 / 2022-04-03 / obs. 187358601
Zannichellia palustris, photographed by Andre Hosper
fig. b Andre Hosper, CC BY 4.0 / obs. 136900321
Zannichellia palustris, photographed by Nolan Exe
fig. c Nolan Exe, CC BY 4.0 / obs. 92901911
Zannichellia palustris, photographed by Quinten Wiegersma
fig. d Quinten Wiegersma, CC BY 4.0 / obs. 78236905
Zannichellia palustris, photographed by Brandon Corder
fig. e Brandon Corder, CC BY 4.0 / obs. 76922188
Zannichellia palustris, photographed by Nolan Exe
fig. f Nolan Exe, CC BY 4.0 / obs. 50012947
Zannichellia palustris, photographed by Millie Basden
fig. g Millie Basden, CC BY 4.0 / obs. 24944107
Zannichellia palustris, photographed by Summit Metro Parks
fig. h Summit Metro Parks, CC BY 4.0 / obs. 46674194

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 182 botanical countries

Regions where Zannichellia palustris is native: Algeria, Botswana, Canary Is., Cape Provinces, Chad, Egypt, Free State, Libya, Madagascar, Morocco, Namibia, Northern Provinces, Rodrigues, Sudan-South Sudan, Tanzania, Tunisia, Afghanistan, Altay, Buryatiya, China North-Central, China South-Central, China Southeast, Chita, Cyprus, East Aegean Is., Gulf States, Inner Mongolia, Iran, Iraq, Irkutsk, Japan, Kamchatka, Kazakhstan, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, Kuril Is., Lebanon-Syria, Manchuria, Mongolia, Nansei-shoto, North Caucasus, Oman, Palestine, Primorye, Qinghai, Sakhalin, Saudi Arabia, Tadzhikistan, Taiwan, Tibet, Transcaucasus, Türkiye, Turkmenistan, Tuva, Uzbekistan, West Siberia, Xinjiang, Yemen, Assam, Bangladesh, India, Myanmar, Nepal, Pakistan, West Himalaya, New South Wales, New Zealand North, New Zealand South, South Australia, Albania, Austria, Baleares, Baltic States, Belarus, Belgium, Bulgaria, Central European Russia, Corse, Czechia-Slovakia, Denmark, East European Russia, Finland, France, Germany, Great Britain, Greece, Hungary, Iceland, Ireland, Italy, Kriti, Krym, Netherlands, North European Russia, Northwest European Russia, Norway, NW. Balkan Pen., Poland, Portugal, Romania, Sardegna, Sicilia, South European Russia, Spain, Sweden, Switzerland, Türkiye-in-Europe, Ukraine, Alabama, Alaska, Alberta, Arizona, Arkansas, British Columbia, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Manitoba, Maryland, Massachusetts, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southwest, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New York, Newfoundland, North Carolina, North Dakota, Nova Scotia, Nunavut, Ohio, Oklahoma, Ontario, Oregon, Pennsylvania, Prince Edward I., Québec, Rhode I., Saskatchewan, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming, Yukon, Argentina Northeast, Argentina Northwest, Argentina South, Bolivia, Chile Central, Colombia, Peru AlgeriaBotswanaCape ProvincesChadEgyptFree StateLibyaMadagascarMoroccoNamibiaNorthern ProvincesSudan-South SudanTanzaniaTunisiaAfghanistanAltayBuryatiyaChina North-CentralChina South-CentralChina SoutheastChitaCyprusEast Aegean Is.Gulf StatesInner MongoliaIranIraqIrkutskJapanKamchatkaKazakhstanKhabarovskKirgizstanKrasnoyarskLebanon-SyriaManchuriaMongoliaNorth CaucasusOmanPalestinePrimoryeQinghaiSakhalinSaudi ArabiaTadzhikistanTaiwanTibetTranscaucasusTürkiyeTurkmenistanTuvaUzbekistanWest SiberiaXinjiangYemenAssamBangladeshIndiaMyanmarNepalPakistanWest HimalayaNew South WalesNew Zealand NorthNew Zealand SouthSouth AustraliaAlbaniaAustriaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCorseCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceHungaryIcelandIrelandItalyKritiKrymNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSiciliaSouth European RussiaSpainSwedenSwitzerlandTürkiye-in-EuropeUkraineAlabamaAlaskaAlbertaArizonaArkansasBritish ColumbiaCaliforniaColoradoConnecticutFloridaIdahoIllinoisIndianaIowaKansasKentuckyLouisianaMaineManitobaMarylandMassachusettsMexico CentralMexico GulfMexico NortheastMexico NorthwestMexico SouthwestMichiganMinnesotaMississippiMissouriMontanaNebraskaNevadaNew BrunswickNew HampshireNew JerseyNew MexicoNew YorkNewfoundlandNorth CarolinaNorth DakotaNova ScotiaNunavutOhioOklahomaOntarioOregonPennsylvaniaPrince Edward I.QuébecSaskatchewanSouth DakotaTennesseeTexasUtahVermontVirginiaWashingtonWest VirginiaWisconsinWyomingYukonArgentina NortheastArgentina NorthwestArgentina SouthBoliviaChile CentralColombiaPeru Canary Is.RodriguesKoreaNansei-shotoBalearesSardegnaDelawareDistrict of ColumbiaRhode I.
Native distribution of Zannichellia palustris, 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. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Alabama ALA NORTHERN AMERICA
Alaska ASK
Alberta ABT
Arizona ARI
Arkansas ARK
British Columbia BRC
California CAL
Colorado COL
Connecticut CNT
Delaware DEL
District of Columbia WDC
Florida FLA
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Louisiana LOU
Maine MAI
Manitoba MAN
Maryland MRY
Massachusetts MAS
Mexico Central MXC
Mexico Gulf MXG
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southwest MXS
Michigan MIC
Minnesota MIN
Mississippi MSI
Missouri MSO
Montana MNT
Nebraska NEB
Nevada NEV
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New Mexico NWM
New York NWY
Newfoundland NFL
North Carolina NCA
North Dakota NDA
Nova Scotia NSC
Nunavut NUN
Ohio OHI
Oklahoma OKL
Ontario ONT
Oregon ORE
Pennsylvania PEN
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
Saskatchewan SAS
South Dakota SDA
Tennessee TEN
Texas TEX
Utah UTA
Vermont VER
Virginia VRG
Washington WAS
West Virginia WVA
Wisconsin WIS
Wyoming WYO
Yukon YUK
Afghanistan AFG ASIA-TEMPERATE
Altay ALT
Buryatiya BRY
China North-Central CHN
China South-Central CHC
China Southeast CHS
Chita CTA
Cyprus CYP
East Aegean Is. EAI
Gulf States GST
Inner Mongolia CHI
Iran IRN
Iraq IRQ
Irkutsk IRK
Japan JAP
Kamchatka KAM
Kazakhstan KAZ
Khabarovsk KHA
Kirgizstan KGZ
Korea KOR
Krasnoyarsk KRA
Kuril Is. KUR
Lebanon-Syria LBS
Manchuria CHM
Mongolia MON
Nansei-shoto NNS
North Caucasus NCS
Oman OMA
Palestine PAL
Primorye PRM
Qinghai CHQ
Sakhalin SAK
Saudi Arabia SAU
Tadzhikistan TZK
Taiwan TAI
Tibet CHT
Transcaucasus TCS
Türkiye TUR
Turkmenistan TKM
Tuva TVA
Uzbekistan UZB
West Siberia WSB
Xinjiang CHX
Yemen YEM
Albania ALB EUROPE
Austria AUT
Baleares BAL
Baltic States BLT
Belarus BLR
Belgium BGM
Bulgaria BUL
Central European Russia RUC
Corse COR
Czechia-Slovakia CZE
Denmark DEN
East European Russia RUE
Finland FIN
France FRA
Germany GER
Great Britain GRB
Greece GRC
Hungary HUN
Iceland ICE
Ireland IRE
Italy ITA
Kriti KRI
Krym KRY
Netherlands NET
North European Russia RUN
Northwest European Russia RUW
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Portugal POR
Romania ROM
Sardegna SAR
Sicilia SIC
South European Russia RUS
Spain SPA
Sweden SWE
Switzerland SWI
Türkiye-in-Europe TUE
Ukraine UKR
Algeria ALG AFRICA
Botswana BOT
Canary Is. CNY
Cape Provinces CPP
Chad CHA
Egypt EGY
Free State OFS
Libya LBY
Madagascar MDG
Morocco MOR
Namibia NAM
Northern Provinces TVL
Rodrigues ROD
Sudan-South Sudan SUD
Tanzania TAN
Tunisia TUN
Assam ASS ASIA-TROPICAL
Bangladesh BAN
India IND
Myanmar MYA
Nepal NEP
Pakistan PAK
West Himalaya WHM
Argentina Northeast AGE SOUTHERN AMERICA
Argentina Northwest AGW
Argentina South AGS
Bolivia BOL
Chile Central CLC
Colombia CLM
Peru PER
New South Wales NSW AUSTRALASIA
New Zealand North NZN
New Zealand South NZS
South Australia SOA

Not drawn on the map: Kuril Is., Great Britain. We hold no public-domain boundary for these regions, so they are listed rather than guessed at.

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 87 synonyms

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.

  • Algoides palustris Lunell
  • Pelta palustris (L.) Dulac
  • Zannichellia aculeata Schur
  • Zannichellia brachystemon J.Gay ex Reut.
  • Zannichellia clausii Tzvelev
  • Zannichellia cotheneti P.Fourn.
  • Zannichellia dentata Willd.
  • Zannichellia dentata subsp. maritima (Nolte ex Hampe) P.Fourn.
  • Zannichellia dentata subsp. pedicellata (Rosén & Wahlenb.) Arcang.
  • Zannichellia dentata subsp. polycarpa (Nolte ex Rchb.) P.Fourn.
  • Zannichellia digyna J.Gay ex Bréb.
  • Zannichellia echinata Lojac.
  • Zannichellia geniculata Gilib.
  • Zannichellia gibberosa Rchb.
  • Zannichellia graminifolia Gilib.
  • Zannichellia indica Morong
  • Zannichellia intermedia Torr.
  • Zannichellia intermedia Nielsen
  • Zannichellia komarovii Tzvelev
  • Zannichellia laevis C.Presl
  • Zannichellia lingulata Clavaud
  • Zannichellia major Boenn. ex Reichenb.
  • Zannichellia major Boenn. ex Rchb.
  • Zannichellia marina Nielsen

and 63 more.

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.