Glyceria fluitans(L.) R.Br.

Floating Sweet-grassFlottin sweet grassSweet GrassWater manna grassflote-grass, floating sweet-grasswater mannagrass

WFO wfo-0000873191 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Glyceria fluitans, photographed by Vladimír Fuka
fig. a Vladimír Fuka, CC BY 4.0 / 2021-08-29 / obs. 154019212
Glyceria fluitans, photographed by Esa Aalto
fig. b Esa Aalto, CC0 1.0 / obs. 146772543
Glyceria fluitans, photographed by Robert H. Wardell
fig. c Robert H. Wardell, CC0 1.0 / obs. 96608881
Glyceria fluitans, photographed by Robert H. Wardell
fig. d Robert H. Wardell, CC0 1.0 / obs. 93643320
Glyceria fluitans, photographed by Gabriel Mayrhofer
fig. e Gabriel Mayrhofer, CC0 1.0 / obs. 85202028
Glyceria fluitans, photographed by Елена Смирнова
fig. f Елена Смирнова, CC BY 4.0 / obs. 78503925
Glyceria fluitans, photographed by Susan Marley
fig. g Susan Marley, CC BY 4.0 / obs. 67792392
Glyceria fluitans, photographed by Susan Marley
fig. h Susan Marley, CC BY 4.0 / obs. 66528081

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.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
1775271
Filed as
Glyceria fluitans (L.) R.Br.
Det. by
D. E. Atha 2015-01-01
Collected
G. V. Nash 1898-07
Origin
US
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 43 botanical countries

Regions where Glyceria fluitans is native: Morocco, East Aegean Is., North Caucasus, Transcaucasus, Türkiye, Turkmenistan, 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, 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 MoroccoEast Aegean Is.North CaucasusTranscaucasusTürkiyeTurkmenistanAlbaniaAustriaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCorseCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceHungaryIcelandIrelandItalyNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSiciliaSouth European RussiaSpainSwedenSwitzerlandTürkiye-in-EuropeUkraine FøroyarSardegna
Native distribution of Glyceria fluitans, 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
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
East Aegean Is. EAI ASIA-TEMPERATE
North Caucasus NCS
Transcaucasus TCS
Türkiye TUR
Turkmenistan TKM
Morocco MOR AFRICA

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.

Where it actually grows measured, from 994 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -12.3 °C -8.6 °C 2.0 °C
Warmest month, mean daily high 18.9 °C 22.7 °C 24.4 °C
Annual rainfall 581 mm 684 mm 1,265 mm
Rainfall in the driest quarter 96 mm 112 mm 229 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 994 research-grade observations of Glyceria fluitans that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Also published as 25 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.

  • Desvauxia fluitans P.Beauv. ex Kunth
  • Festuca fluitans L.
  • Festucaria heisteri Fabr. ex Steud.
  • Glyceria acuminata Schur
  • Glyceria denticulata Dumort.
  • Glyceria fluitans var. acutiflora Döll
  • Glyceria fluitans var. adscendens Wahlenb.
  • Glyceria fluitans var. denticulata Dumort.
  • Glyceria fluitans var. festucacea Fr.
  • Glyceria fluitans var. inflata H.Post
  • Glyceria fluitans var. integra Dumort.
  • Glyceria fluitans var. islandica Á.Löve
  • Glyceria fluitans var. maritima Gray
  • Glyceria fluitans var. terrestris Gray
  • Glyceria fluitans var. triticea (Fr.) Andersson
  • Glyceria fluitans var. vivipara Gray
  • Glyceria integra Dumort.
  • Hydrochloa fluitans (L.) Hartm.
  • Melica fluitans (L.) Raspail
  • Molinia fluitans (L.) Hartm.
  • Molinia plicata Hartm.
  • Panicularia brachyphylla Nash
  • Panicularia fluitans (L.) Kuntze
  • Poa barrelieri Biv.

and 1 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.