Ruppia maritimaL.

Beaked TasselweedDitch-grassDitchgrassSpecies code: RmWidgeongrassbeaked tasselweedwidgeongrass

WFO wfo-0000770081 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Ruppia maritima, photographed by Andre Hosper
fig. a Andre Hosper, CC BY 4.0 / 2022-04-15 / obs. 188249711
Ruppia maritima, photographed by 葉子
fig. b 葉子, CC0 1.0 / obs. 108276271
Ruppia maritima, photographed by ritirene
fig. c ritirene, CC BY 4.0 / obs. 104866564
Ruppia maritima, photographed by 葉子
fig. d 葉子, CC0 1.0 / obs. 59383260
Ruppia maritima, photographed by coenobita
fig. e coenobita, CC BY 4.0 / obs. 24295750
Ruppia maritima, photographed by Cheng-Tao Lin
fig. f Cheng-Tao Lin, CC BY 4.0 / obs. 18283956
Ruppia maritima, photographed by Cheng-Tao Lin
fig. g Cheng-Tao Lin, CC BY 4.0 / obs. 18284335
Ruppia maritima, photographed by S.MORE
fig. h S.MORE, CC0 1.0 / obs. 111952319

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 200 botanical countries

Regions where Ruppia maritima is native: Aldabra, Algeria, Angola, Azores, Canary Is., Cape Provinces, Cape Verde, DR Congo, Egypt, Equatorial Guinea, Eritrea, Free State, Gabon, Ghana, KwaZulu-Natal, Libya, Madagascar, Madeira, Mauritania, Mauritius, Morocco, Namibia, Nigeria, Réunion, Rodrigues, Senegal, Socotra, Sudan-South Sudan, Tanzania, Tunisia, Altay, China North-Central, China Southeast, Chita, Cyprus, East Aegean Is., Gulf States, Hainan, Iran, Iraq, Japan, Kazakhstan, Korea, Krasnoyarsk, Lebanon-Syria, Magadan, Mongolia, Nansei-shoto, North Caucasus, Ogasawara-shoto, Oman, Palestine, Primorye, Qinghai, Sakhalin, Saudi Arabia, Sinai, Tadzhikistan, Taiwan, Transcaucasus, Türkiye, Turkmenistan, Uzbekistan, Xinjiang, Yemen, Assam, Bangladesh, India, Malaya, Myanmar, Pakistan, Philippines, South China Sea, Sri Lanka, Thailand, Vietnam, West Himalaya, New South Wales, Northern Territory, Queensland, South Australia, Victoria, Western Australia, Baleares, Baltic States, Belarus, Belgium, Bulgaria, Central European Russia, Corse, Denmark, East European Russia, Finland, Føroyar, France, Germany, Great Britain, Greece, 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, Türkiye-in-Europe, Ukraine, Alabama, Alaska, British Columbia, California, Connecticut, Delaware, Florida, Georgia, Louisiana, Maine, Maryland, Massachusetts, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Mississippi, New Brunswick, New Hampshire, New Jersey, New York, Newfoundland, North Carolina, Nova Scotia, Ontario, Oregon, Prince Edward I., Québec, Rhode I., Saskatchewan, South Carolina, Texas, Virginia, Washington, Fiji, Gilbert Is., Hawaii, Marianas, New Caledonia, Phoenix Is., Samoa, Tonga, Argentina Northeast, Argentina Northwest, Aruba, Bahamas, Belize, Bermuda, Bolivia, Brazil Northeast, Brazil South, Brazil Southeast, Cayman Is., Central American Pacific Is., Chile Central, Colombia, Costa Rica, Cuba, Ecuador, El Salvador, French Guiana, Galápagos, Guatemala, Guyana, Haiti, Honduras, Jamaica, Leeward Is., Netherlands Antilles, Nicaragua, Panamá, Paraguay, Peru, Puerto Rico, Suriname, Trinidad-Tobago, Turks-Caicos Is., Venezuela, Venezuelan Antilles, Windward Is. AlgeriaAngolaCape ProvincesDR CongoEgyptEquatorial GuineaEritreaFree StateGabonGhanaKwaZulu-NatalLibyaMadagascarMauritaniaMoroccoNamibiaNigeriaSenegalSudan-South SudanTanzaniaTunisiaAltayChina North-CentralChina SoutheastChitaCyprusEast Aegean Is.Gulf StatesHainanIranIraqJapanKazakhstanKrasnoyarskLebanon-SyriaMagadanMongoliaNorth CaucasusOmanPalestinePrimoryeQinghaiSakhalinSaudi ArabiaSinaiTadzhikistanTaiwanTranscaucasusTürkiyeTurkmenistanUzbekistanXinjiangYemenAssamBangladeshIndiaMalayaMyanmarPakistanPhilippinesSri LankaThailandVietnamWest HimalayaNew South WalesNorthern TerritoryQueenslandSouth AustraliaVictoriaWestern AustraliaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCorseDenmarkEast European RussiaFinlandFranceGermanyGreeceIcelandIrelandItalyKritiKrymNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSiciliaSouth European RussiaSpainSwedenTürkiye-in-EuropeUkraineAlabamaAlaskaBritish ColumbiaCaliforniaConnecticutFloridaGeorgiaLouisianaMaineMarylandMassachusettsMexico CentralMexico GulfMexico NortheastMexico NorthwestMexico SoutheastMexico SouthwestMississippiNew BrunswickNew HampshireNew JerseyNew YorkNewfoundlandNorth CarolinaNova ScotiaOntarioOregonPrince Edward I.QuébecSaskatchewanSouth CarolinaTexasVirginiaWashingtonFijiHawaiiNew CaledoniaArgentina NortheastArgentina NorthwestBelizeBoliviaBrazil NortheastBrazil SouthBrazil SoutheastCentral American Pacific Is.Chile CentralColombiaCosta RicaCubaEcuadorEl SalvadorFrench GuianaGuatemalaGuyanaHaitiHondurasJamaicaNicaraguaPanamáParaguayPeruPuerto RicoSurinameTrinidad-TobagoVenezuela AldabraAzoresCanary Is.Cape VerdeMadeiraMauritiusRéunionRodriguesKoreaNansei-shotoSouth China SeaBalearesFøroyarSardegnaDelawareRhode I.MarianasSamoaTongaArubaBahamasBermudaCayman Is.GalápagosLeeward Is.Netherlands AntillesTurks-Caicos Is.Venezuelan AntillesWindward Is.
Native distribution of Ruppia maritima, 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
Argentina Northeast AGE SOUTHERN AMERICA
Argentina Northwest AGW
Aruba ARU
Bahamas BAH
Belize BLZ
Bermuda BER
Bolivia BOL
Brazil Northeast BZE
Brazil South BZS
Brazil Southeast BZL
Cayman Is. CAY
Central American Pacific Is. CPI
Chile Central CLC
Colombia CLM
Costa Rica COS
Cuba CUB
Ecuador ECU
El Salvador ELS
French Guiana FRG
Galápagos GAL
Guatemala GUA
Guyana GUY
Haiti HAI
Honduras HON
Jamaica JAM
Leeward Is. LEE
Netherlands Antilles NLA
Nicaragua NIC
Panamá PAN
Paraguay PAR
Peru PER
Puerto Rico PUE
Suriname SUR
Trinidad-Tobago TRT
Turks-Caicos Is. TCI
Venezuela VEN
Venezuelan Antilles VNA
Windward Is. WIN
Alabama ALA NORTHERN AMERICA
Alaska ASK
British Columbia BRC
California CAL
Connecticut CNT
Delaware DEL
Florida FLA
Georgia GEO
Louisiana LOU
Maine MAI
Maryland MRY
Massachusetts MAS
Mexico Central MXC
Mexico Gulf MXG
Mexico Northeast MXE
Mexico Northwest MXN
Mexico Southeast MXT
Mexico Southwest MXS
Mississippi MSI
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New York NWY
Newfoundland NFL
North Carolina NCA
Nova Scotia NSC
Ontario ONT
Oregon ORE
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
Saskatchewan SAS
South Carolina SCA
Texas TEX
Virginia VRG
Washington WAS
Altay ALT ASIA-TEMPERATE
China North-Central CHN
China Southeast CHS
Chita CTA
Cyprus CYP
East Aegean Is. EAI
Gulf States GST
Hainan CHH
Iran IRN
Iraq IRQ
Japan JAP
Kazakhstan KAZ
Korea KOR
Krasnoyarsk KRA
Lebanon-Syria LBS
Magadan MAG
Mongolia MON
Nansei-shoto NNS
North Caucasus NCS
Ogasawara-shoto OGA
Oman OMA
Palestine PAL
Primorye PRM
Qinghai CHQ
Sakhalin SAK
Saudi Arabia SAU
Sinai SIN
Tadzhikistan TZK
Taiwan TAI
Transcaucasus TCS
Türkiye TUR
Turkmenistan TKM
Uzbekistan UZB
Xinjiang CHX
Yemen YEM
Baleares BAL EUROPE
Baltic States BLT
Belarus BLR
Belgium BGM
Bulgaria BUL
Central European Russia RUC
Corse COR
Denmark DEN
East European Russia RUE
Finland FIN
Føroyar FOR
France FRA
Germany GER
Great Britain GRB
Greece GRC
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
Türkiye-in-Europe TUE
Ukraine UKR
Aldabra ALD AFRICA
Algeria ALG
Angola ANG
Azores AZO
Canary Is. CNY
Cape Provinces CPP
Cape Verde CVI
DR Congo ZAI
Egypt EGY
Equatorial Guinea EQG
Eritrea ERI
Free State OFS
Gabon GAB
Ghana GHA
KwaZulu-Natal NAT
Libya LBY
Madagascar MDG
Madeira MDR
Mauritania MTN
Mauritius MAU
Morocco MOR
Namibia NAM
Nigeria NGA
Réunion REU
Rodrigues ROD
Senegal SEN
Socotra SOC
Sudan-South Sudan SUD
Tanzania TAN
Tunisia TUN
Assam ASS ASIA-TROPICAL
Bangladesh BAN
India IND
Malaya MLY
Myanmar MYA
Pakistan PAK
Philippines PHI
South China Sea SCS
Sri Lanka SRL
Thailand THA
Vietnam VIE
West Himalaya WHM
Fiji FIJ PACIFIC
Gilbert Is. GIL
Hawaii HAW
Marianas MRN
New Caledonia NWC
Phoenix Is. PHX
Samoa SAM
Tonga TON
New South Wales NSW AUSTRALASIA
Northern Territory NTA
Queensland QLD
South Australia SOA
Victoria VIC
Western Australia WAU

Not drawn on the map: Socotra, Ogasawara-shoto, Great Britain, Gilbert Is., Phoenix Is.. 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 58 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.

  • Buccaferrea maritima (L.) Lunell
  • Ruppia andina Phil.
  • Ruppia brachypus J.Gay
  • Ruppia brachypus subsp. bahusiensis Lindstr.
  • Ruppia brevipes Bertol. ex Griseb.
  • Ruppia cirrhosa subsp. longipes (Hagstr.) Á.Löve
  • Ruppia curvicarpa A.Nelson
  • Ruppia intermedia Thed.
  • Ruppia intermedia C.G.H.Thed.
  • Ruppia marina Fr.
  • Ruppia maritima f. aculeata Hagstr.
  • Ruppia maritima f. brevirostris C.Agardh
  • Ruppia maritima f. curvirorstris H.St.John & Fosberg
  • Ruppia maritima f. pectinata Hagstr.
  • Ruppia maritima prol. brachypus (J.Gay) Rouy
  • Ruppia maritima prol. brevirostris
  • Ruppia maritima prol. curvicarpa (A.Nelson) Graebn.
  • Ruppia maritima subsp. brachypus Á.Löve
  • Ruppia maritima subsp. brachypus (J.Gay) Bonnier & Layens
  • Ruppia maritima subsp. brachypus (J.Gay) Schlegel
  • Ruppia maritima subsp. brevirostris C.Agardh
  • Ruppia maritima subsp. intermedia (C.G.H.Thed.) Piper & Beattie
  • Ruppia maritima subsp. obliqua (Griseb. & Schenk) Á.Löve & D.Löve
  • Ruppia maritima subsp. rostellata (W.D.J.Koch ex Rchb.) Asch. & Graebn.

and 34 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.