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 21 botanical countries
| Region | TDWG code | Continent |
|---|---|---|
| Alaska | ASK | NORTHERN AMERICA |
| Alberta | ABT | |
| Aleutian Is. | ALU | |
| British Columbia | BRC | |
| California | CAL | |
| Colorado | COL | |
| Idaho | IDA | |
| Mexico Central | MXC | |
| Mexico Gulf | MXG | |
| Mexico Northeast | MXE | |
| Mexico Northwest | MXN | |
| Montana | MNT | |
| Nevada | NEV | |
| Oregon | ORE | |
| Saskatchewan | SAS | |
| South Dakota | SDA | |
| Utah | UTA | |
| Washington | WAS | |
| Wyoming | WYO | |
| Japan | JAP | ASIA-TEMPERATE |
| Kuril Is. | KUR |
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 511 observations
| Condition | 5th percentile | Median | 95th percentile |
|---|---|---|---|
| Coldest month, mean daily low | -16.4 °C | -4.5 °C | 4.2 °C |
| Warmest month, mean daily high | 16.2 °C | 21.5 °C | 28.0 °C |
| Annual rainfall | 517 mm | 1,331 mm | 3,595 mm |
| Rainfall in the driest quarter | 60 mm | 151 mm | 409 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 511 research-grade observations of Juncus ensifolius 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 Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.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 6 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.
- Juncus ensifolius var. ensifolius
- Juncus ensifolius var. major E.Mey.
- Juncus novikovii A.P.Khokhr.
- Juncus oligocephalus Satake & Ohwi
- Juncus xiphioides var. macranthus Engelm.
- Juncus xiphioides var. triandrus Engelm.
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.