Juncus filiformisL.

thread rush

WFO wfo-0000776448 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Juncus filiformis, photographed by Nina Filippova
fig. a Nina Filippova, CC BY 4.0 / 2021-09-27 / obs. 160158477
Juncus filiformis, photographed by Nina Filippova
fig. b Nina Filippova, CC BY 4.0 / obs. 150972048
Juncus filiformis, photographed by Nina Filippova
fig. c Nina Filippova, CC BY 4.0 / obs. 150964888
Juncus filiformis, photographed by Jens-Christian Svenning
fig. d Jens-Christian Svenning, CC BY 4.0 / obs. 148314219
Juncus filiformis, photographed by Jens-Christian Svenning
fig. e Jens-Christian Svenning, CC BY 4.0 / obs. 145945565
Juncus filiformis, photographed by Jason Grant
fig. f Jason Grant, CC BY 4.0 / obs. 146317547
Juncus filiformis, photographed by Jens-Christian Svenning
fig. g Jens-Christian Svenning, CC BY 4.0 / obs. 145786327
Juncus filiformis, photographed by Jens-Christian Svenning
fig. h Jens-Christian Svenning, CC BY 4.0 / obs. 145453604

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 62 botanical countries

Regions where Juncus filiformis is native: Altay, Buryatiya, Chita, Irkutsk, Japan, Kamchatka, Khabarovsk, Krasnoyarsk, Kuril Is., Magadan, Manchuria, Mongolia, North Caucasus, Primorye, Sakhalin, Transcaucasus, Türkiye, Tuva, West Siberia, Xinjiang, Yakutiya, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Russia, Czechia-Slovakia, Denmark, East European Russia, Finland, France, Germany, Great Britain, Greece, Iceland, Italy, Netherlands, North European Russia, Northwest European Russia, Norway, NW. Balkan Pen., Poland, Romania, Spain, Sweden, Switzerland, Alaska, Alberta, British Columbia, Colorado, Greenland, Labrador, Manitoba, Minnesota, New York, Newfoundland, Northwest Territories, Saskatchewan, Vermont, Wisconsin, Yukon AltayBuryatiyaChitaIrkutskJapanKamchatkaKhabarovskKrasnoyarskMagadanManchuriaMongoliaNorth CaucasusPrimoryeSakhalinTranscaucasusTürkiyeTuvaWest SiberiaXinjiangYakutiyaAustriaBaltic StatesBelarusBelgiumBulgariaCentral European RussiaCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceIcelandItalyNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandRomaniaSpainSwedenSwitzerlandAlaskaAlbertaBritish ColumbiaColoradoGreenlandLabradorManitobaMinnesotaNew YorkNewfoundlandNorthwest TerritoriesSaskatchewanVermontWisconsinYukon
Native distribution of Juncus filiformis, 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
Austria AUT EUROPE
Baltic States BLT
Belarus BLR
Belgium BGM
Bulgaria BUL
Central European Russia RUC
Czechia-Slovakia CZE
Denmark DEN
East European Russia RUE
Finland FIN
France FRA
Germany GER
Great Britain GRB
Greece GRC
Iceland ICE
Italy ITA
Netherlands NET
North European Russia RUN
Northwest European Russia RUW
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Romania ROM
Spain SPA
Sweden SWE
Switzerland SWI
Altay ALT ASIA-TEMPERATE
Buryatiya BRY
Chita CTA
Irkutsk IRK
Japan JAP
Kamchatka KAM
Khabarovsk KHA
Krasnoyarsk KRA
Kuril Is. KUR
Magadan MAG
Manchuria CHM
Mongolia MON
North Caucasus NCS
Primorye PRM
Sakhalin SAK
Transcaucasus TCS
Türkiye TUR
Tuva TVA
West Siberia WSB
Xinjiang CHX
Yakutiya YAK
Alaska ASK NORTHERN AMERICA
Alberta ABT
British Columbia BRC
Colorado COL
Greenland GNL
Labrador LAB
Manitoba MAN
Minnesota MIN
New York NWY
Newfoundland NFL
Northwest Territories NWT
Saskatchewan SAS
Vermont VER
Wisconsin WIS
Yukon YUK

Not drawn on the map: Kuril Is., Great Britain. 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 1,629 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -26.0 °C -12.2 °C -6.1 °C
Warmest month, mean daily high 14.9 °C 21.8 °C 23.8 °C
Annual rainfall 549 mm 706 mm 1,781 mm
Rainfall in the driest quarter 69 mm 110 mm 317 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 1,629 research-grade observations of Juncus filiformis 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 15 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 balticus f. pusillus (Fr.) Neuman
  • Juncus filiformis f. flaccidus Borza & Nyár.
  • Juncus filiformis f. flaccidus Zapał.
  • Juncus filiformis f. prostratus Freiberg
  • Juncus filiformis f. pusillus (Fr.) Neuman
  • Juncus filiformis lus. prolifer Asch. & Graebn.
  • Juncus filiformis unranked transsilvanicus (Schur) Asch. & Graebn.
  • Juncus filiformis var. aphyllus E.Mey.
  • Juncus filiformis var. foliatus E.Mey.
  • Juncus filiformis var. kulczynskii Racib.
  • Juncus filiformis var. pluriflorus Krylov
  • Juncus filiformis var. pusillus Fr.
  • Juncus filiformis var. transsilvanicus (Schur) Nyman
  • Juncus transsilvanicus Schur
  • Juncus trichodes Steud.

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.