Catabrosa aquatica(L.) P.Beauv.

Whorl-grasswater whorl-grasswater whorlgrass

WFO wfo-0000858385 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Catabrosa aquatica, photographed by Liubov Ilminska
fig. a Liubov Ilminska, CC0 1.0 / 2022-06-06 / obs. 204048235
Catabrosa aquatica, photographed by Skjold Søndergaard
fig. b Skjold Søndergaard, CC BY 4.0 / obs. 138724596
Catabrosa aquatica, photographed by pratvmvmbrosvm
fig. c pratvmvmbrosvm, CC0 1.0 / obs. 134893503
Catabrosa aquatica, photographed by Patrick Hacker
fig. d Patrick Hacker, CC BY 4.0 / obs. 113285488
Catabrosa aquatica, photographed by Natalya Ivanova
fig. e Natalya Ivanova, CC BY 4.0 / obs. 77376104
Catabrosa aquatica, photographed by Dmitriy Bochkov
fig. f Dmitriy Bochkov, CC BY 4.0 / obs. 43847704
Catabrosa aquatica, photographed by Matt Lavin
fig. g Matt Lavin, CC BY 4.0 / obs. 154532931
Catabrosa aquatica, photographed by Michael D. Pirie
fig. h Michael D. Pirie, CC BY 4.0 / obs. 155137486

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 99 botanical countries

Regions where Catabrosa aquatica is native: Algeria, Libya, Morocco, Afghanistan, Altay, Buryatiya, China North-Central, China South-Central, Chita, Inner Mongolia, Iran, Iraq, Kazakhstan, Kirgizstan, Krasnoyarsk, Lebanon-Syria, Mongolia, North Caucasus, Palestine, Qinghai, Tadzhikistan, Tibet, Transcaucasus, Türkiye, Turkmenistan, Tuva, Uzbekistan, West Siberia, Xinjiang, East Himalaya, Nepal, Pakistan, West Himalaya, Albania, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Russia, Corse, Czechia-Slovakia, Denmark, East European Russia, Finland, Føroyar, France, Germany, Great Britain, Greece, Hungary, Iceland, Ireland, Italy, Krym, Netherlands, North European Russia, Northwest European Russia, Norway, NW. Balkan Pen., Poland, Romania, Sardegna, Sicilia, South European Russia, Spain, Sweden, Switzerland, Türkiye-in-Europe, Ukraine, Alberta, Arizona, Arkansas, British Columbia, Colorado, Greenland, Idaho, Iowa, Labrador, Manitoba, Montana, Nebraska, Nevada, New Brunswick, New Mexico, Newfoundland, North Dakota, Ontario, Oregon, Prince Edward I., Québec, Saskatchewan, South Dakota, Utah, Washington, Wisconsin, Wyoming, Argentina South, Chile South AlgeriaLibyaMoroccoAfghanistanAltayBuryatiyaChina North-CentralChina South-CentralChitaInner MongoliaIranIraqKazakhstanKirgizstanKrasnoyarskLebanon-SyriaMongoliaNorth CaucasusPalestineQinghaiTadzhikistanTibetTranscaucasusTürkiyeTurkmenistanTuvaUzbekistanWest SiberiaXinjiangEast HimalayaNepalPakistanWest HimalayaAlbaniaAustriaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCorseCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceHungaryIcelandIrelandItalyKrymNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandRomaniaSiciliaSouth European RussiaSpainSwedenSwitzerlandTürkiye-in-EuropeUkraineAlbertaArizonaArkansasBritish ColumbiaColoradoGreenlandIdahoIowaLabradorManitobaMontanaNebraskaNevadaNew BrunswickNew MexicoNewfoundlandNorth DakotaOntarioOregonPrince Edward I.QuébecSaskatchewanSouth DakotaUtahWashingtonWisconsinWyomingArgentina SouthChile South FøroyarSardegna
Native distribution of Catabrosa aquatica, 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
Albania ALB EUROPE
Austria AUT
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
Føroyar FOR
France FRA
Germany GER
Great Britain GRB
Greece GRC
Hungary HUN
Iceland ICE
Ireland IRE
Italy ITA
Krym KRY
Netherlands NET
North European Russia RUN
Northwest European Russia RUW
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Romania ROM
Sardegna SAR
Sicilia SIC
South European Russia RUS
Spain SPA
Sweden SWE
Switzerland SWI
Türkiye-in-Europe TUE
Ukraine UKR
Alberta ABT NORTHERN AMERICA
Arizona ARI
Arkansas ARK
British Columbia BRC
Colorado COL
Greenland GNL
Idaho IDA
Iowa IOW
Labrador LAB
Manitoba MAN
Montana MNT
Nebraska NEB
Nevada NEV
New Brunswick NBR
New Mexico NWM
Newfoundland NFL
North Dakota NDA
Ontario ONT
Oregon ORE
Prince Edward I. PEI
Québec QUE
Saskatchewan SAS
South Dakota SDA
Utah UTA
Washington WAS
Wisconsin WIS
Wyoming WYO
Afghanistan AFG ASIA-TEMPERATE
Altay ALT
Buryatiya BRY
China North-Central CHN
China South-Central CHC
Chita CTA
Inner Mongolia CHI
Iran IRN
Iraq IRQ
Kazakhstan KAZ
Kirgizstan KGZ
Krasnoyarsk KRA
Lebanon-Syria LBS
Mongolia MON
North Caucasus NCS
Palestine PAL
Qinghai CHQ
Tadzhikistan TZK
Tibet CHT
Transcaucasus TCS
Türkiye TUR
Turkmenistan TKM
Tuva TVA
Uzbekistan UZB
West Siberia WSB
Xinjiang CHX
East Himalaya EHM ASIA-TROPICAL
Nepal NEP
Pakistan PAK
West Himalaya WHM
Algeria ALG AFRICA
Libya LBY
Morocco MOR
Argentina South AGS SOUTHERN AMERICA
Chile South CLS

Not drawn on the map: Great Britain. We hold no public-domain boundary for this region, so it is 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 65 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.

  • Agrostis tillierii Willd. ex Steud.
  • Aira aquatica L.
  • Aira aquatica var. duplicata Chaub.
  • Aira aquatica var. multiplicata Chaub.
  • Aira aquatica var. ochroleuca (Dumort.) Lej.
  • Aira scabra Zuccagni
  • Aira viridula Poir.
  • Catabrosa airoides Chevall.
  • Catabrosa angusta (Stapf) L.Liu
  • Catabrosa aquatica f. latifolia (Heuff.) Soó
  • Catabrosa aquatica f. schurii Soó
  • Catabrosa aquatica f. uniflora (Gray) Holmb.
  • Catabrosa aquatica f. zapalowiczii Soó
  • Catabrosa aquatica subsp. aquatica
  • Catabrosa aquatica subsp. capusii (Franch.) Tzvelev
  • Catabrosa aquatica subsp. ochroleuca (Dumort.) Nyman
  • Catabrosa aquatica subsp. pseudairoides (J.Herrm.) Tzvelev
  • Catabrosa aquatica var. angusta Stapf
  • Catabrosa aquatica var. aquatica
  • Catabrosa aquatica var. atrata Tzvelev
  • Catabrosa aquatica var. chionophila Post
  • Catabrosa aquatica var. laurentiana Fernald
  • Catabrosa aquatica var. littoralis Parn.
  • Catabrosa aquatica var. major Peterm.

and 41 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.