Cyperus schweinitziiTorr.

Schweinitz's flatsedge

WFO wfo-0000382221 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Cyperus schweinitzii, photographed by Mary Krieger
fig. a Mary Krieger, CC BY 4.0 / 2020-08-22 / obs. 91579681
Cyperus schweinitzii, photographed by Owen Strickland
fig. b Owen Strickland, CC BY 4.0 / obs. 91180368
Cyperus schweinitzii, photographed by Jeff D Hansen
fig. c Jeff D Hansen, CC BY 4.0 / obs. 85322732
Cyperus schweinitzii, photographed by Zihao Wang
fig. d Zihao Wang, CC BY 4.0 / obs. 45478474
Cyperus schweinitzii, photographed by aarongunnar
fig. e aarongunnar, CC BY 4.0 / obs. 23222675
Cyperus schweinitzii, photographed by Zihao Wang
fig. f Zihao Wang, CC BY 4.0 / obs. 21811758
Cyperus schweinitzii, photographed by aarongunnar
fig. g aarongunnar, CC BY 4.0 / obs. 24699509
Cyperus schweinitzii, photographed by er-birds
fig. h er-birds, CC BY 4.0 / obs. 151904671

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 28 botanical countries

Regions where Cyperus schweinitzii is native: Alberta, Colorado, Illinois, Indiana, Iowa, Kentucky, Manitoba, Massachusetts, Mexico Northeast, Michigan, Minnesota, Missouri, Montana, New Jersey, New Mexico, New York, Ohio, Oklahoma, Ontario, Pennsylvania, Québec, Saskatchewan, South Dakota, Texas, Utah, Washington, Wisconsin, Wyoming AlbertaColoradoIllinoisIndianaIowaKentuckyManitobaMassachusettsMexico NortheastMichiganMinnesotaMissouriMontanaNew JerseyNew MexicoNew YorkOhioOklahomaOntarioPennsylvaniaQuébecSaskatchewanSouth DakotaTexasUtahWashingtonWisconsinWyoming
Native distribution of Cyperus schweinitzii, 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
Alberta ABT NORTHERN AMERICA
Colorado COL
Illinois ILL
Indiana INI
Iowa IOW
Kentucky KTY
Manitoba MAN
Massachusetts MAS
Mexico Northeast MXE
Michigan MIC
Minnesota MIN
Missouri MSO
Montana MNT
New Jersey NWJ
New Mexico NWM
New York NWY
Ohio OHI
Oklahoma OKL
Ontario ONT
Pennsylvania PEN
Québec QUE
Saskatchewan SAS
South Dakota SDA
Texas TEX
Utah UTA
Washington WAS
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.

Also published as 3 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.

  • Chlorocyperus schweinitzii (Torr.) Palla
  • Cyperus alterniflorus Schwein.
  • Mariscus schweinitzii (Torr.) T.Koyama

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.