Eleocharis obtusa(Willd.) Schult.

Blunt spike rushBlunt spikerushblunt spikerush

WFO wfo-0000405442 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Eleocharis obtusa, photographed by Violet T.
fig. a Violet T., CC BY 4.0 / 2022-06-07 / obs. 204473991
Eleocharis obtusa, photographed by Quinten Wiegersma
fig. b Quinten Wiegersma, CC BY 4.0 / obs. 139517675
Eleocharis obtusa, photographed by Quinten Wiegersma
fig. c Quinten Wiegersma, CC BY 4.0 / obs. 139547762
Eleocharis obtusa, photographed by Yann Kemper
fig. d Yann Kemper, CC0 1.0 / obs. 132978812
Eleocharis obtusa, photographed by Reuven Martin
fig. e Reuven Martin, CC0 1.0 / obs. 91704220
Eleocharis obtusa, photographed by Quinten Wiegersma
fig. f Quinten Wiegersma, CC BY 4.0 / obs. 84455034
Eleocharis obtusa, photographed by Carter Dorscht
fig. g Carter Dorscht, CC0 1.0 / obs. 83303850
Eleocharis obtusa, photographed by Summit Metro Parks
fig. h Summit Metro Parks, CC BY 4.0 / obs. 47659492

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 50 botanical countries

Regions where Eleocharis obtusa is native: Alabama, Arkansas, British Columbia, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Nova Scotia, Ohio, Oklahoma, Ontario, Oregon, Pennsylvania, Prince Edward I., Québec, Rhode I., South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming, Argentina Northeast AlabamaArkansasBritish ColumbiaCaliforniaColoradoConnecticutFloridaGeorgiaIdahoIllinoisIndianaIowaKentuckyLouisianaMaineMarylandMassachusettsMichiganMinnesotaMississippiMissouriNebraskaNevadaNew HampshireNew JerseyNew MexicoNew YorkNorth CarolinaNova ScotiaOhioOklahomaOntarioOregonPennsylvaniaPrince Edward I.QuébecSouth CarolinaSouth DakotaTennesseeTexasVermontVirginiaWashingtonWest VirginiaWisconsinWyomingArgentina Northeast DelawareDistrict of ColumbiaRhode I.
Native distribution of Eleocharis obtusa, 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
Alabama ALA NORTHERN AMERICA
Arkansas ARK
British Columbia BRC
California CAL
Colorado COL
Connecticut CNT
Delaware DEL
District of Columbia WDC
Florida FLA
Georgia GEO
Idaho IDA
Illinois ILL
Indiana INI
Iowa IOW
Kentucky KTY
Louisiana LOU
Maine MAI
Maryland MRY
Massachusetts MAS
Michigan MIC
Minnesota MIN
Mississippi MSI
Missouri MSO
Nebraska NEB
Nevada NEV
New Hampshire NWH
New Jersey NWJ
New Mexico NWM
New York NWY
North Carolina NCA
Nova Scotia NSC
Ohio OHI
Oklahoma OKL
Ontario ONT
Oregon ORE
Pennsylvania PEN
Prince Edward I. PEI
Québec QUE
Rhode I. RHO
South Carolina SCA
South Dakota SDA
Tennessee TEN
Texas TEX
Vermont VER
Virginia VRG
Washington WAS
West Virginia WVA
Wisconsin WIS
Wyoming WYO
Argentina Northeast AGE SOUTHERN AMERICA

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 656 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -15.2 °C -6.5 °C 4.1 °C
Warmest month, mean daily high 22.2 °C 27.1 °C 32.4 °C
Annual rainfall 860 mm 1,099 mm 1,544 mm
Rainfall in the driest quarter 119 mm 219 mm 308 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 656 research-grade observations of Eleocharis obtusa 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.

  • Eleocharis obtusa var. ellipsoidalis Fernald ex Svenson
  • Eleocharis obtusa var. gigantea Fernald
  • Eleocharis obtusa var. jejuna Fernald
  • Eleocharis obtusa var. obtusa
  • Eleocharis obtusa var. peasei Svenson
  • Scirpus obtusus Willd.
  • Trichophyllum obtusum (Willd.) House

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.