Cyperus bipartitus

Cyperus bipartitus
Conservation status
Least Concern  (IUCN 3.1) [1]
Secure  (NatureServe) [2]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Clade:	Commelinids
Order:	Poales
Family:	Cyperaceae
Genus:	Cyperus
Species:	C. bipartitus
Binomial name
Cyperus bipartitus Torr. [3]
Synonyms [4]
Homotypic synonyms Cyperus diandrus var. bipartitus(Torr.) Kük. Pycreus bipartitus(Torr.) C.B.Clarke Heterotypic synonyms Chlorocyperus rivularis(Kunth) Rikli Cyperus angustifoliusA.Dietr. Cyperus argentinusC.B.Clarke Cyperus bicolorBarton Cyperus bigelowiiSteud. Cyperus bipartitus f. elongatus(Boeckeler) Mohlenbr. Cyperus bipartitus f. elutus(C.B.Clarke) Mohlenbr. Cyperus castaneusBigelow Cyperus diandrus var. castaneus(Pursh) Torr. Cyperus flavescens var. bicolorFarw. Cyperus flavescens var. castaneusPursh Cyperus lagunettoSteud. Cyperus niger var. rivularis(Kunth) V.E.Grant Cyperus pauperPhil. Cyperus rivularisKunth Cyperus rivularis var. acutatusC.B.Clarke Cyperus rivularis f. acutatus(C.B.Clarke) Kük. Cyperus rivularis var. depauperatusC.B.Clarke Cyperus rivularis f. depauperatus(C.B.Clarke) Kük. Cyperus rivularis var. elongatusBoeckeler Cyperus rivularis var. elutusC.B.Clarke Cyperus rivularis f. elutus(C.B.Clarke) Kük. Cyperus rivularis subsp. lagunetto(Steud.) Kük. Cyperus rivularis var. lagunetto(Steud.) O'Neill Cyperus rivularis f. subacaulisKük. Cyperus tenuiculusKunth Pycreus lagunetto(Steud.) C.B.Clarke Pycreus rivularis(Kunth) Palla

Cyperus bipartitus, also known as slender flatsedge, river cyperus, or shining flatsedge, is a species of flowering plant in the sedge family Cyperaceae. It is native to the Americas. It is not to be confused with Cyperus gracilis , which is also known as "slender flatsedge".

Description

Cyperus bipartitus is an annual sedge with fibrous roots. There are multiple stems at the base of the plant. A stem rarely exceeds 25 cm (9.8 in) in height. Above the stem, the inflorescence bears clusters of spikelets, each with numerous florets. There are 2–3 leaf-like bracts at the base of the inflorescence. The main cluster of spikelets at the top of the stem is stalkless, accompanied by 0–4 additional clusters on stalks up to 3 cm long. Each cluster supports 3–10 flattened spikelets. The terminal spikelet is usually erect. A spikelet consists of 10–26 florets, each covered by a scale (a type of bract in sedges and grasses). Each floret is bisexual with 2–3  anthers and a single style with two branched stigmas. The anthers and stigmas emerge from the axil of the floral scale but a perianth is absent. The fruit is an achene, a black disc about a millimeter wide. ^{[5] [6] [7]}

Cyperus bipartitus is sometimes confused with Cyperus diandrus , both of which have pigmented floral scales, ranging in color from reddish-brown to purplish-brown. The two species may be distinguished by the pattern of pigmentation in the scales, ^{[8] [9]} but occasionally the scales will be entirely pale greenish-white. ^[10] Cyperus diandrus has conspicuous, persistent styles while Cyperus bipartitus does not.

Taxonomy

Cyperus bipartitus was named and described by the American botanist John Torrey in 1836. ^[3] Its type specimen was collected in New Orleans. ^[11] As of February 2026 ^[update] , the botanical name Cyperus bipartitusTorr. is widely accepted. ^{[4] [12] [13] [14] [15]}

Distribution and habitat

Cyperus bipartitus is native to the Americas, from southeastern Canada to northern Argentina. ^[4] It is found in wet environments such as lakes, sandbars, and ditches at elevations to 1,500 metres (4,900 ft). ^[5]

Ecology

Cyperus dentatus is a flowering plant whose season runs from July to October in the southeastern United States. ^[16]

Conservation

As of February 2026 ^[update] , the NatureServe global conservation status of Cyperus bipartitus is secure (G5). ^[2]

See also

• List of Cyperus species
• Glossary of botanical terms

References

1. Lansdown, R.V. (2016). "Pycreus bipartitus". The IUCN Red List of Threatened Species. Retrieved 2 February 2026.
2. NatureServe (30 January 2026). "Cyperus bipartitus". NatureServe Explorer. Arlington, Virginia. Retrieved 2 February 2026.
3. "Cyperus bipartitusTorr.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 2 February 2026.
4. "Cyperus bipartitusTorr.". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 2 February 2026.
5. Tucker, Gordon C.; Marcks, Brian G.; Carter, J. Richard (2002). "Cyperus bipartitus". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 23. New York and Oxford: Oxford University Press. Retrieved 2 February 2026– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
6. Tucker, Gordon C. (2012). "Cyperus bipartitus". Jepson eFlora. University of California, Berkeley. Retrieved 2 February 2026.
7. "Cyperus bipartitus (Shining Flatsedge)". Minnesota Wildflowers. Retrieved 3 February 2026.
8. "Cyperus bipartitus — shining flatsedge". Go Botany. Native Plant Trust. Retrieved 2 February 2026.
9. "Comparison of Cyperus bipartitus and Cyperus diandrus spikelets". Minnesota Wildflowers. Retrieved 3 February 2026.
10. Reznicek, A. A.; Voss, E. G.; Walters, B. S. (February 2011). "Cyperus". Michigan Flora Online. University of Michigan. Retrieved 2 February 2026.
11. Torrey (1836), p. 257.
12. "Cyperus bipartitusTorr.". WFO Plant List. Retrieved 2 February 2026.
13. "Cyperus bipartitusTorrey". Database of Vascular Plants of Canada. Retrieved 4 February 2026.
14. NRCS. "Cyperus bipartitus". PLANTS Database. United States Department of Agriculture (USDA). Retrieved 2 February 2026.
15. "Cyperus bipartitusTorr.". eFloraMEX. Retrieved 4 February 2026.
16. "Cyperus bipartitusTorrey". Flora of the Southeastern United States. Retrieved 2 February 2026.

Bibliography

• Torrey, John (1836). "Monograph of the North American Cyperaceae". Annals of the Lyceum of Natural History of New York. 3: 239–448. Retrieved 12 January 2026.

External links

• "Cyperus bipartitus". Lady Bird Johnson Wildflower Center. The University of Texas at Austin. Retrieved 2 February 2026.
• Kartesz, John T. (2014). "Cyperus bipartitus". State-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). Retrieved 2 February 2026.
• Kartesz, John T. (2014). "Cyperus bipartitus". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). Retrieved 2 February 2026.
• "Cyperus bipartitus Torrey slender flatsedge". Calflora. Retrieved 12 January 2014.
• Photo gallery