Eriophorum angustifoliumHonck.

common cottongrasstall cottongrass

WFO wfo-0000414886 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Eriophorum angustifolium, photographed by Rafael Medina
fig. a Rafael Medina, CC BY 4.0 / 2022-06-09 / obs. 205984122

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 91 botanical countries

Regions where Eriophorum angustifolium is native: Altay, Amur, Buryatiya, China South-Central, Chita, Inner Mongolia, Irkutsk, Kamchatka, Kazakhstan, Khabarovsk, Korea, Krasnoyarsk, Kuril Is., Magadan, Manchuria, Mongolia, North Caucasus, Primorye, Sakhalin, Transcaucasus, Türkiye, West Siberia, Yakutiya, Albania, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Russia, 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, South European Russia, Spain, Svalbard, Sweden, Switzerland, Alaska, Alberta, Aleutian Is., British Columbia, Colorado, Greenland, Idaho, Illinois, Indiana, Iowa, Labrador, Maine, Manitoba, Michigan, Minnesota, Montana, Nebraska, New Brunswick, New Mexico, New York, Newfoundland, North Dakota, Northwest Territories, Nova Scotia, Nunavut, Ontario, Oregon, Prince Edward I., Québec, Saskatchewan, South Dakota, Washington, Wisconsin, Wyoming, Yukon AltayAmurBuryatiyaChina South-CentralChitaInner MongoliaIrkutskKamchatkaKazakhstanKhabarovskKrasnoyarskMagadanManchuriaMongoliaNorth CaucasusPrimoryeSakhalinTranscaucasusTürkiyeWest SiberiaYakutiyaAlbaniaAustriaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceHungaryIcelandIrelandItalyNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSouth European RussiaSpainSvalbardSwedenSwitzerlandAlaskaAlbertaBritish ColumbiaColoradoGreenlandIdahoIllinoisIndianaIowaLabradorMaineManitobaMichiganMinnesotaMontanaNebraskaNew BrunswickNew MexicoNew YorkNewfoundlandNorth DakotaNorthwest TerritoriesNova ScotiaNunavutOntarioOregonPrince Edward I.QuébecSaskatchewanSouth DakotaWashingtonWisconsinWyomingYukon KoreaFøroyar
Native distribution of Eriophorum angustifolium, 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
Alaska ASK NORTHERN AMERICA
Alberta ABT
Aleutian Is. ALU
British Columbia BRC
Colorado COL
Greenland GNL
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Labrador LAB
Maine MAI
Manitoba MAN
Michigan MIC
Minnesota MIN
Montana MNT
Nebraska NEB
New Brunswick NBR
New Mexico NWM
New York NWY
Newfoundland NFL
North Dakota NDA
Northwest Territories NWT
Nova Scotia NSC
Nunavut NUN
Ontario ONT
Oregon ORE
Prince Edward I. PEI
Québec QUE
Saskatchewan SAS
South Dakota SDA
Washington WAS
Wisconsin WIS
Wyoming WYO
Yukon YUK
Albania ALB EUROPE
Austria AUT
Baltic States BLT
Belarus BLR
Belgium BGM
Bulgaria BUL
Central European Russia RUC
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
South European Russia RUS
Spain SPA
Svalbard SVA
Sweden SWE
Switzerland SWI
Altay ALT ASIA-TEMPERATE
Amur AMU
Buryatiya BRY
China South-Central CHC
Chita CTA
Inner Mongolia CHI
Irkutsk IRK
Kamchatka KAM
Kazakhstan KAZ
Khabarovsk KHA
Korea KOR
Krasnoyarsk KRA
Kuril Is. KUR
Magadan MAG
Manchuria CHM
Mongolia MON
North Caucasus NCS
Primorye PRM
Sakhalin SAK
Transcaucasus TCS
Türkiye TUR
West Siberia WSB
Yakutiya YAK

Not drawn on the map: Kuril Is., Great Britain, Aleutian 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.

Flowering 167 in flower of 655 examined

Proportion of examined Eriophorum angustifolium in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 0 0 too few examined
Mar 2 2 too few examined
Apr 24 41 59% 43% to 72%
May 47 106 44% 35% to 54%
Jun 63 255 25% 20% to 30%
Jul 28 155 18% 13% to 25%
Aug 2 70 3% 1% to 10%
Sep 0 19 0% 0% to 17%
Oct 1 5 20% 4% to 62%
Nov 0 2 too few examined
Dec 0 0 too few examined

Peak flowering in Apr. Each bar is the share of Eriophorum angustifolium observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 167 of 655 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 5 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 1,983 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -26.5 °C -7.6 °C 3.7 °C
Warmest month, mean daily high 11.2 °C 18.4 °C 25.0 °C
Annual rainfall 437 mm 1,035 mm 3,044 mm
Rainfall in the driest quarter 43 mm 179 mm 434 mm

It is found where winters are arctic. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,983 research-grade observations of Eriophorum angustifolium 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. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 55 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.

  • Eriophorum alpicola Schur
  • Eriophorum angustifolium f. rubrovaginatum Raymond
  • Eriophorum angustifolium f. scammanianum Raymond
  • Eriophorum angustifolium f. uniceps Th.Fr.
  • Eriophorum angustifolium subsp. minus (Dalla Torre) Holub
  • Eriophorum angustifolium subsp. scabriusculum Hultén
  • Eriophorum angustifolium subsp. subarcticum (Vassil) Hultén
  • Eriophorum angustifolium subsp. subarcticum (V.N.Vassil.) Hultén ex Kartesz & Gandhi
  • Eriophorum angustifolium var. alpinum Gaudin
  • Eriophorum angustifolium var. alpinum Gray
  • Eriophorum angustifolium var. angustifolium
  • Eriophorum angustifolium var. brevifolium Torr.
  • Eriophorum angustifolium var. coloratum Hultén
  • Eriophorum angustifolium var. congestum Mert. & W.D.J.Koch
  • Eriophorum angustifolium var. elatius Mert. & W.D.J.Koch
  • Eriophorum angustifolium var. giganteum Hultén
  • Eriophorum angustifolium var. gracile Nyman
  • Eriophorum angustifolium var. laxum Mert. & W.D.J.Koch
  • Eriophorum angustifolium var. megastachyon Nutt.
  • Eriophorum angustifolium var. minus W.D.J.Koch
  • Eriophorum angustifolium var. minus Bellynck
  • Eriophorum angustifolium var. triquetrum Hartm.
  • Eriophorum angustifolium var. vaillantii (Poit. & Turpin) Gaudin
  • Eriophorum dubium Hegetschw.

and 31 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.