Calamagrostis purpurascensR.Br.

purple reedgrass

WFO wfo-0000857902 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Calamagrostis purpurascens, photographed by Syd Cannings
fig. a Syd Cannings, CC BY 4.0 / 2021-05-11 / obs. 128348593

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
Smithsonian, US National Herbarium
Accession
US 3318559
Filed as
Calamagrostis purpurascens R.Br.
Det. by
Soreng, Robert J., Research Associate (BOT), Smithsonian Institution - National Museum of Natural History (UNITED STATES)
Collected
P. M. Peterson & C. R. Annable 1994-08-31
Origin
US
The sheet
View the digitised specimen (CC0 1.0)

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 39 botanical countries

Regions where Calamagrostis purpurascens is native: Amur, Buryatiya, Chita, Kamchatka, Khabarovsk, Krasnoyarsk, Kuril Is., Magadan, Mongolia, Primorye, Yakutiya, Svalbard, Alaska, Alberta, Aleutian Is., British Columbia, California, Colorado, Greenland, Idaho, Manitoba, Mexico Northeast, Minnesota, Montana, Nevada, New Mexico, Newfoundland, North Dakota, Northwest Territories, Nunavut, Ontario, Oregon, Québec, Saskatchewan, South Dakota, Utah, Washington, Wyoming, Yukon AmurBuryatiyaChitaKamchatkaKhabarovskKrasnoyarskMagadanMongoliaPrimoryeYakutiyaSvalbardAlaskaAlbertaBritish ColumbiaCaliforniaColoradoGreenlandIdahoManitobaMexico NortheastMinnesotaMontanaNevadaNew MexicoNewfoundlandNorth DakotaNorthwest TerritoriesNunavutOntarioOregonQuébecSaskatchewanSouth DakotaUtahWashingtonWyomingYukon
Native distribution of Calamagrostis purpurascens, 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.
RegionTDWG codeContinent
Alaska ASK NORTHERN AMERICA
Alberta ABT
Aleutian Is. ALU
British Columbia BRC
California CAL
Colorado COL
Greenland GNL
Idaho IDA
Manitoba MAN
Mexico Northeast MXE
Minnesota MIN
Montana MNT
Nevada NEV
New Mexico NWM
Newfoundland NFL
North Dakota NDA
Northwest Territories NWT
Nunavut NUN
Ontario ONT
Oregon ORE
Québec QUE
Saskatchewan SAS
South Dakota SDA
Utah UTA
Washington WAS
Wyoming WYO
Yukon YUK
Amur AMU ASIA-TEMPERATE
Buryatiya BRY
Chita CTA
Kamchatka KAM
Khabarovsk KHA
Krasnoyarsk KRA
Kuril Is. KUR
Magadan MAG
Mongolia MON
Primorye PRM
Yakutiya YAK
Svalbard SVA EUROPE

Not drawn on the map: Kuril Is., 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.

Where it actually grows measured, from 253 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -29.0 °C -20.2 °C -14.6 °C
Warmest month, mean daily high 14.9 °C 19.6 °C 22.5 °C
Annual rainfall 320 mm 421 mm 917 mm
Rainfall in the driest quarter 33 mm 48 mm 134 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 253 research-grade observations of Calamagrostis purpurascens 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 27 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 purpurascens (R.Br.) Schult. & Schult.f.
  • Calamagrostis arctica Vasey
  • Calamagrostis arundinacea f. purpurascens (R.Br.) Gelert
  • Calamagrostis arundinacea var. purpurascens (R.Br.) Porsild
  • Calamagrostis czekanowskiana Litv.
  • Calamagrostis laricina (Louis-Marie) Louis-Marie
  • Calamagrostis lepageana Louis-Marie
  • Calamagrostis maltei (Polunin) Á.Löve & D.Löve
  • Calamagrostis poluninii T.J.Sørensen
  • Calamagrostis purpurascens f. compacta Louis-Marie
  • Calamagrostis purpurascens subsp. arctica (Vasey) Hultén
  • Calamagrostis purpurascens subsp. maltei (Polunin) A.E.Porsild
  • Calamagrostis purpurascens var. arctica (Vasey) Kearney
  • Calamagrostis purpurascens var. laricina Louis-Marie
  • Calamagrostis purpurascens var. maltei Polunin
  • Calamagrostis purpurascens var. purpurascens
  • Calamagrostis purpurascens var. typica Louis-Marie
  • Calamagrostis purpurascens var. vaseyi M.E.Jones
  • Calamagrostis sylvatica var. americana Vasey
  • Calamagrostis sylvatica var. purpurascens Thurb. ex Vasey
  • Calamagrostis vaseyi Beal
  • Calamagrostis wiluica Litv. ex Petrov
  • Calamagrostis yukonensis Nash
  • Deschampsia congestiformis W.E.Booth

and 3 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.