Carex scirpoideaMichx.

northern singlespike sedge

WFO wfo-0000351089 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Carex scirpoidea, photographed by Trevor Van Loon
fig. a Trevor Van Loon, CC BY 4.0 / 2021-07-23 / obs. 149998177
Carex scirpoidea, photographed by Ellyne Geurts
fig. b Ellyne Geurts, CC0 1.0 / obs. 159331656
Carex scirpoidea, photographed by Syd Cannings
fig. c Syd Cannings, CC BY 4.0 / obs. 137401193
Carex scirpoidea, photographed by Ida B D Jacobsen
fig. d Ida B D Jacobsen, CC BY 4.0 / obs. 136108844
Carex scirpoidea, photographed by Caleb Catto
fig. e Caleb Catto, CC BY 4.0 / obs. 73666455
Carex scirpoidea, photographed by Quinten Wiegersma
fig. f Quinten Wiegersma, CC BY 4.0 / obs. 39467650
Carex scirpoidea, photographed by Quinten Wiegersma
fig. g Quinten Wiegersma, CC BY 4.0 / obs. 39467582
Carex scirpoidea, photographed by Todd Boland
fig. h Todd Boland, CC BY 4.0 / obs. 112561815

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 35 botanical countries

Regions where Carex scirpoidea is native: Kamchatka, Magadan, Yakutiya, Norway, Alaska, Alberta, British Columbia, California, Colorado, Greenland, Idaho, Labrador, Maine, Manitoba, Michigan, Minnesota, Montana, Nevada, New Brunswick, New Hampshire, New York, Newfoundland, North Dakota, Northwest Territories, Nova Scotia, Nunavut, Ontario, Oregon, Québec, Saskatchewan, Utah, Vermont, Washington, Wyoming, Yukon KamchatkaMagadanYakutiyaNorwayAlaskaAlbertaBritish ColumbiaCaliforniaColoradoGreenlandIdahoLabradorMaineManitobaMichiganMinnesotaMontanaNevadaNew BrunswickNew HampshireNew YorkNewfoundlandNorth DakotaNorthwest TerritoriesNova ScotiaNunavutOntarioOregonQuébecSaskatchewanUtahVermontWashingtonWyomingYukon
Native distribution of Carex scirpoidea, 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
British Columbia BRC
California CAL
Colorado COL
Greenland GNL
Idaho IDA
Labrador LAB
Maine MAI
Manitoba MAN
Michigan MIC
Minnesota MIN
Montana MNT
Nevada NEV
New Brunswick NBR
New Hampshire NWH
New York NWY
Newfoundland NFL
North Dakota NDA
Northwest Territories NWT
Nova Scotia NSC
Nunavut NUN
Ontario ONT
Oregon ORE
Québec QUE
Saskatchewan SAS
Utah UTA
Vermont VER
Washington WAS
Wyoming WYO
Yukon YUK
Kamchatka KAM ASIA-TEMPERATE
Magadan MAG
Yakutiya YAK
Norway NOR EUROPE

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 74 in flower of 95 examined

Peak flowering in May. Each bar is the share of Carex scirpoidea 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. 74 of 95 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 7 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 432 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -30.5 °C -16.0 °C -9.6 °C
Warmest month, mean daily high 9.4 °C 18.2 °C 23.6 °C
Annual rainfall 276 mm 841 mm 2,228 mm
Rainfall in the driest quarter 30 mm 140 mm 427 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 432 research-grade observations of Carex scirpoidea 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 19 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.

  • Carex athabascensis F.J.Herm.
  • Carex michauxii Schwein.
  • Carex pseudoscirpoidea Rydb.
  • Carex scirpiformis Mack.
  • Carex scirpina Tuck.
  • Carex scirpina Tuck. ex Boott
  • Carex scirpoidea f. basigyna Lange
  • Carex scirpoidea subsp. convoluta (Kük.) Dunlop
  • Carex scirpoidea subsp. pseudoscirpoidea (Rydb.) Dunlop
  • Carex scirpoidea subsp. scirpoidea
  • Carex scirpoidea subsp. stenochlaena (Holm) Á.Löve & D.Löve
  • Carex scirpoidea var. europaea Kük.
  • Carex scirpoidea var. scirpiformis (Mack.) O'Neill & Duman
  • Carex scirpoidea var. typica B.Boivin
  • Carex scirpoides Sartwell
  • Carex stenochlaena (Holm) Mack.
  • Carex wormskioldiana Hornem.
  • Carex wormskioldii (Raf.) Drejer
  • Physiglochis wormskioldii Raf.

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.