Juncus dudleyiWiegand

Dudley's rush

WFO wfo-0000776337 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Juncus dudleyi, photographed by Summit Metro Parks
fig. a Summit Metro Parks, CC BY 4.0 / 2020-07-24 / obs. 87485865
Juncus dudleyi, photographed by Owen Strickland
fig. b Owen Strickland, CC BY 4.0 / obs. 85901390
Juncus dudleyi, photographed by Quinten Wiegersma
fig. c Quinten Wiegersma, CC BY 4.0 / obs. 75665660
Juncus dudleyi, photographed by Quinten Wiegersma
fig. d Quinten Wiegersma, CC BY 4.0 / obs. 75066060
Juncus dudleyi, photographed by Rob Foster
fig. e Rob Foster, CC BY 4.0 / obs. 52351199
Juncus dudleyi, photographed by Allan Harris
fig. f Allan Harris, CC0 1.0 / obs. 25355955
Juncus dudleyi, photographed by Kenneth Burdick
fig. g Kenneth Burdick, CC BY 4.0 / obs. 92596780
Juncus dudleyi, photographed by Nancy Navarre
fig. h Nancy Navarre, CC0 1.0 / obs. 141559844

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 59 botanical countries

Regions where Juncus dudleyi is native: Alberta, Arizona, Arkansas, British Columbia, California, Colorado, Connecticut, Delaware, District of Columbia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Labrador, Louisiana, Maine, Manitoba, Maryland, Massachusetts, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southwest, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New York, Newfoundland, North Dakota, Nova Scotia, Ohio, Oklahoma, Ontario, Oregon, Pennsylvania, Prince Edward I., Québec, Rhode I., Saskatchewan, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming AlbertaArizonaArkansasBritish ColumbiaCaliforniaColoradoConnecticutIdahoIllinoisIndianaIowaKansasKentuckyLabradorLouisianaMaineManitobaMarylandMassachusettsMexico CentralMexico GulfMexico NortheastMexico SouthwestMichiganMinnesotaMississippiMissouriMontanaNebraskaNevadaNew BrunswickNew HampshireNew JerseyNew MexicoNew YorkNewfoundlandNorth DakotaNova ScotiaOhioOklahomaOntarioOregonPennsylvaniaPrince Edward I.QuébecSaskatchewanSouth DakotaTennesseeTexasUtahVermontVirginiaWashingtonWest VirginiaWisconsinWyoming DelawareDistrict of ColumbiaRhode I.
Native distribution of Juncus dudleyi, 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. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Alberta ABT NORTHERN AMERICA
Arizona ARI
Arkansas ARK
British Columbia BRC
California CAL
Colorado COL
Connecticut CNT
Delaware DEL
District of Columbia WDC
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Labrador LAB
Louisiana LOU
Maine MAI
Manitoba MAN
Maryland MRY
Massachusetts MAS
Mexico Central MXC
Mexico Gulf MXG
Mexico Northeast MXE
Mexico Southwest MXS
Michigan MIC
Minnesota MIN
Mississippi MSI
Missouri MSO
Montana MNT
Nebraska NEB
Nevada NEV
New Brunswick NBR
New Hampshire NWH
New Jersey NWJ
New Mexico NWM
New York NWY
Newfoundland NFL
North Dakota NDA
Nova Scotia NSC
Ohio OHI
Oklahoma OKL
Ontario ONT
Oregon ORE
Pennsylvania PEN
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
Saskatchewan SAS
South Dakota SDA
Tennessee TEN
Texas TEX
Utah UTA
Vermont VER
Virginia VRG
Washington WAS
West Virginia WVA
Wisconsin WIS
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 268 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -16.4 °C -9.2 °C -1.8 °C
Warmest month, mean daily high 22.0 °C 26.0 °C 30.8 °C
Annual rainfall 735 mm 975 mm 1,277 mm
Rainfall in the driest quarter 74 mm 178 mm 261 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 268 research-grade observations of Juncus dudleyi 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 7 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 andreanus Weath.
  • Juncus coarctatus Willd. ex Spreng.
  • Juncus platycaulos Kunth
  • Juncus tenuis subsp. dudleyi (Wiegand) P.Fourn.
  • Juncus tenuis var. dudleyi (Wiegand) F.J.Herm.
  • Juncus tenuis var. platycaulos (Kunth) Buchenau
  • Juncus tenuis var. uniflorus Farw.

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.