Plate 1 figs. a–h · 8 separate observations
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 19 botanical countries
| Region | TDWG code | Continent |
|---|---|---|
| Alberta | ABT | NORTHERN AMERICA |
| Arizona | ARI | |
| British Columbia | BRC | |
| California | CAL | |
| Colorado | COL | |
| Idaho | IDA | |
| Mexico Northwest | MXN | |
| Missouri | MSO | |
| Montana | MNT | |
| Nebraska | NEB | |
| Nevada | NEV | |
| New Mexico | NWM | |
| North Dakota | NDA | |
| Oregon | ORE | |
| Saskatchewan | SAS | |
| South Dakota | SDA | |
| Utah | UTA | |
| Washington | WAS | |
| Wyoming | WYO |
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 209 observations
| Condition | 5th percentile | Median | 95th percentile |
|---|---|---|---|
| Coldest month, mean daily low | -14.6 °C | -8.5 °C | -2.4 °C |
| Warmest month, mean daily high | 21.8 °C | 27.3 °C | 32.4 °C |
| Annual rainfall | 208 mm | 403 mm | 720 mm |
| Rainfall in the driest quarter | 21 mm | 43 mm | 93 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 209 research-grade observations of Carex douglasii 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 Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.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 13 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 douglasii f. brunnea Olney
- Carex douglasii f. brunnea (Olney) Kük.
- Carex douglasii f. meekii (Dewey) Kük.
- Carex douglasii var. brunnea Olney
- Carex douglasii var. densispicata Dewey
- Carex douglasii var. laxiflora L.H.Bailey
- Carex douglasii var. minor Olney
- Carex douglasii var. williamsii Rydb.
- Carex fendleriana Boeckeler
- Carex irrasa L.H.Bailey
- Carex meekii Dewey
- Carex nuttallii Dewey
- Carex usta L.H.Bailey
Sourcesevery claim on this page
- World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
- iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
- Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
- 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.