Calamagrostis canadensis(Michx.) P.Beauv.

Bluejoint Reed GrassCanada BluejointCanadian Reedgrassbluejointbluejoint reedgrass

WFO wfo-0000857112 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Calamagrostis canadensis, photographed by Étienne Lacroix-Carignan
fig. a Étienne Lacroix-Carignan, CC0 1.0 / 2021-10-23 / obs. 165159499
Calamagrostis canadensis, photographed by Henry "Nick" Robertson
fig. b Henry "Nick" Robertson, CC BY-SA 4.0 / obs. 151478586
Calamagrostis canadensis, photographed by Jason Grant
fig. c Jason Grant, CC BY 4.0 / obs. 146317701
Calamagrostis canadensis, photographed by Loopy30
fig. d Loopy30, CC BY-SA 4.0 / obs. 138627326
Calamagrostis canadensis, photographed by Henry "Nick" Robertson
fig. e Henry "Nick" Robertson, CC BY-SA 4.0 / obs. 138368123
Calamagrostis canadensis, photographed by Cheryl McCleary-Catalano
fig. f Cheryl McCleary-Catalano, CC BY 4.0 / obs. 96868494
Calamagrostis canadensis, photographed by Bex Goreham
fig. g Bex Goreham, CC BY 4.0 / obs. 94263430
Calamagrostis canadensis, photographed by Alex
fig. h Alex, CC0 1.0 / obs. 92329368

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
02236069
Filed as
Calamagrostis canadensis var. canadensis
Det. by
D. E. Atha 2013-01-01
Collected
D. E. Atha 2013-08-01
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 57 botanical countries

Regions where Calamagrostis canadensis is native: Alaska, Alberta, Arizona, British Columbia, California, Colorado, Connecticut, Delaware, District of Columbia, Georgia, Greenland, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Labrador, Maine, Manitoba, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New York, Newfoundland, North Carolina, North Dakota, Northwest Territories, Nova Scotia, Nunavut, Ohio, Ontario, Oregon, Pennsylvania, Prince Edward I., Québec, Rhode I., Saskatchewan, South Dakota, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming, Yukon AlaskaAlbertaArizonaBritish ColumbiaCaliforniaColoradoConnecticutGeorgiaGreenlandIdahoIllinoisIndianaIowaKansasKentuckyLabradorMaineManitobaMarylandMassachusettsMichiganMinnesotaMissouriMontanaNebraskaNevadaNew BrunswickNew HampshireNew JerseyNew MexicoNew YorkNewfoundlandNorth CarolinaNorth DakotaNorthwest TerritoriesNova ScotiaNunavutOhioOntarioOregonPennsylvaniaPrince Edward I.QuébecSaskatchewanSouth DakotaTennesseeUtahVermontVirginiaWashingtonWest VirginiaWisconsinWyomingYukon DelawareDistrict of ColumbiaRhode I.
Native distribution of Calamagrostis canadensis, 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
Arizona ARI
British Columbia BRC
California CAL
Colorado COL
Connecticut CNT
Delaware DEL
District of Columbia WDC
Georgia GEO
Greenland GNL
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Labrador LAB
Maine MAI
Manitoba MAN
Maryland MRY
Massachusetts MAS
Michigan MIC
Minnesota MIN
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
Northwest Territories NWT
Nova Scotia NSC
Nunavut NUN
Ohio OHI
Ontario ONT
Oregon ORE
Pennsylvania PEN
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
Saskatchewan SAS
South Dakota SDA
Tennessee TEN
Utah UTA
Vermont VER
Virginia VRG
Washington WAS
West Virginia WVA
Wisconsin WIS
Wyoming WYO
Yukon YUK

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 1,682 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -21.7 °C -13.1 °C -4.8 °C
Warmest month, mean daily high 17.4 °C 23.2 °C 27.7 °C
Annual rainfall 459 mm 987 mm 2,137 mm
Rainfall in the driest quarter 49 mm 179 mm 328 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,682 research-grade observations of Calamagrostis canadensis 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 57 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.

  • Arundo agrostoides Pursh
  • Arundo canadensis Michx.
  • Arundo cinnoides Muhl.
  • Arundo confinis Willd.
  • Arundo conoides Eaton
  • Arundo fissa Willd. ex Steud.
  • Arundo glauca Muhl.
  • Calamagrostis agrostoides (Pursh) Spreng.
  • Calamagrostis alaskana Kearney
  • Calamagrostis anomala Suksd.
  • Calamagrostis atropurpurea Nash
  • Calamagrostis blanda Beal
  • Calamagrostis canadensis subsp. acuminata (Vasey ex Shear & Rydb.) Piper & Beattie
  • Calamagrostis canadensis subsp. canadensis
  • Calamagrostis canadensis var. acuminata Vasey ex Shear & Rydb.
  • Calamagrostis canadensis var. campestris Kearney
  • Calamagrostis canadensis var. canadensis
  • Calamagrostis canadensis var. dorei B.Boivin
  • Calamagrostis canadensis var. dubia (Scribn. & Tweedy) Vasey
  • Calamagrostis canadensis var. imberbis (Stebbins) C.L.Hitchc.
  • Calamagrostis canadensis var. lactea (Beal) C.L.Hitchc.
  • Calamagrostis canadensis var. macouniana (Vasey) Stebbins
  • Calamagrostis canadensis var. pallida (Vasey & Scribn.) Stebbins
  • Calamagrostis canadensis var. robusta Vasey

and 33 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.