Cyperus odoratus

Fragrant flatsedge
Conservation status
	; Least Concern (IUCN 3.1)
	; Secure (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Clade:	Commelinids
Order:	Poales
Family:	Cyperaceae
Genus:	Cyperus
Species:	C. odoratus
Binomial name
	Cyperus odoratus; L.
Synonyms
	Cyperus odoratus Diclidium odoratum(L.) Schrad. ex Nees ; Papyrus odorata(L.) Willd. ; Papyrus odorata(L.) Kunth ; Torulinium odoratum(L.) S.S.Hooper ; ; C. o. subsp. odoratus Cyperus bracteolatusSteud. ; Cyperus californicusS.Watson ; Cyperus carruthiiAlph.Wood ; Cyperus consociusSteud. ex Jard. ; Cyperus cubanusLiebm. ; Cyperus densiflorusG.Mey. ; Cyperus distansG.Mey., nom. illeg. ; Cyperus eggersiiBoeckeler ; Cyperus eggersii var. laticepsKük. ; Cyperus engelmanniiSteud. ; Cyperus erythrorhizusTorr. ; Cyperus familiarisSteud. ; Cyperus ferax var. bulbiferBarros ; Cyperus ferax var. densiflorus(G.Mey.) Kük. ; Cyperus ferax var. engelmannii(Steud.) Kük. ex Osten ; Cyperus ferax subsp. engelmannii(Steud.) Kük. ; Cyperus ferax var. maximiliani(Schrad. ex Nees) Boeckeler ; Cyperus ferax var. novae-hannoverae(Boeckeler) Kük. ; Cyperus ferax f. parvus(Boeckeler) Kük. ; Cyperus ferax subsp. speciosus(Vahl) Kük. ; Cyperus ferax var. squarrosus(Britton) Kük. ; Cyperus feroxVahl ; Cyperus ferruginescensBoeckeler ; Cyperus flavicomusPursh, nom. illeg. ; Cyperus flexuosusGriseb., nom. illeg. ; Cyperus fossarumLiebm. ; Cyperus fossarumSchltdl., nom. illeg. ; Cyperus fragilisLiebm. ; Cyperus granadinusLiebm. ; Cyperus haenkeiJ.Presl & C.Presl ; Cyperus hamiltoniiKunth ; Cyperus horizontalisSteud., nom. illeg. ; Cyperus huarmensis(Kunth) M.C.Johnst. ; Cyperus jubaeiflorusRudge ; Cyperus laetus var. obtusiflorusBoeckeler ; Cyperus lenticularisSteud. ; Cyperus lomentaceusNees & Meyen ex Kunth ; Cyperus longispicatusNorton, nom. illeg. ; Cyperus lucidusKunth, nom. illeg. ; Cyperus macrocephalus var. eggersii(Boeckeler) S.D.Jones, Wipff & R.Carter ; Cyperus maximiliani(Schrad. ex Nees) Griseb. ; Cyperus michauxianusSchult. ; Cyperus multibracteatusBoeckeler ; Cyperus multicepsHook. & Arn., nom. illeg. ; Cyperus nitidulusBoeckeler ; Cyperus nortoniiA.Heller ; Cyperus novae-hannoveraeBoeckeler ; Cyperus odoratus var. attenuatusFosberg & Sachet ; Cyperus odoratus var. curtispiculusFosberg & Sachet ; Cyperus odoratus var. engelmannii(Steud.) R.Carter, S.D.Jones & Wipff ; Cyperus odoratus var. novae-hannoverae(Boeckeler) Fosberg & Sachet ; Cyperus odoratus var. squarrosus(Britton) S.D.Jones, Wipff & R.Carter ; Cyperus oerstediiLiebm. ; Cyperus parvispiculatusBoeckeler ; Cyperus parvusBoeckeler, nom. illeg. ; Cyperus pennatusBoeckeler, nom. illeg. ; Cyperus phleoidesSeem., nom. illeg. ; Cyperus poeoidesDesv. ; Cyperus pohlianus(Nees) Kuntze ; Cyperus prescottianusHook. & Arn. ; Cyperus pseudostrigosusSteud. ; Cyperus raiateensisJ.W.Moore ; Cyperus raphiostachysLink ; Cyperus reineckeiBoeckeler ; Cyperus rufinusLiebm. ; Cyperus sanctae-crucisLiebm. ; Cyperus speciosusTorr., nom. illeg. ; Cyperus speciosusVahl ; Cyperus speciosus var. ferruginescens(Boeckeler) Britton ; Cyperus speciosus var. parvusBritton ; Cyperus speciosus var. squarrosusBritton ; Cyperus stellatusRudge ; Cyperus tenuiorEngelm. ; Cyperus vahliiBoeckeler, nom. illeg. ; Cyperus virginicusJacq. ex Steud. ; Diclidium auriculatumNees ; Diclidium lenticulareSchrad. ex Nees ; Diclidium lomentaceumNees ; Diclidium maximilianiSchrad. ex Nees ; Diclidium reinwardtiiSchrad. ex Nees ; Diclidium uliginosumSchrad. ex Nees ; Mariscus familiaris(Steud.) T.Koyama ; Mariscus huarmensisKunth ; Mariscus pohlianusNees ; Mariscus rhaphiostachysLiebm. ; Torulinium confertumDesv. ; Torulinium eggersii(Boeckeler) C.B.Clarke ; Torulinium macrocephalum var. davidseiC.D.Adams ; Torulinium macrocephalum var. eggersii(Boeckeler) C.D.Adams ; Torulinium michauxianumC.B.Clarke ; ; C. o. subsp. transcaucasicus Cyperus ferax subsp. transcaucasicusKük. ; Torulinium caucasicumPalla ; Torulinium ferax subsp. caucasicum(Palla) Hadac ; ;

Last updated November 05, 2025

Cyperus odoratus is a species of flowering plant in the sedge family Cyperaceae. It is known by the common names fragrant flatsedge and rusty flatsedge. It has a pantropical distribution that extends into the temperate regions of North and South America. The species is quite variable and may in fact be more than one species included under a single name.

Description

Cyperus odoratus sensu lato is an annual sedge approaching half a meter in height on average but known to grow much taller. It usually has some long, thin leaves around the base of the plant. The inflorescence is made up of one to several cylindrical spikes, each resembling a bottle brush. There are 5 to 8 leaf-like bracts at the base of the inflorescence. Each of the spikes bears a large number of flat, oval-shaped spikelets. Each spikelet is usually light brown to reddish-brown and has a few to over 20 flowers. Each flower is covered by a tough, flat scale (a kind of bract) with a visible midvein. The fruit is a flat achene less than two millimeters long.^[7]^[8]

Cyperus odoratus sensu stricto is similar to Cyperus engelmannii . The floral scales of Cyperus odoratus are overlapping. In contrast, the mature floral scales of Cyperus engelmannii do not overlap, that is, the tip of each scale does not reach the base of the next scale on the same side of the spikelet. The mature achenes of Cyperus odoratus are slightly ellipsoid, while those of Cyperus engelmannii are narrow with linear (parallel) edges.^[9]^[10] The widths of fully developed achenes are 0.5–0.7 mm and 0.3–0.4 mm, respectively.^[11]

Cyperus odoratus and Cyperus engelmannii are the only two Cyperus species in temperate North America with spikelets that eventually break into one-seeded segments.^[12] At maturity, each spikelet breaks into segments each consisting of a scale and an achene held together by a portion of the floral axis.^[8]

Taxonomy

Cyperus odoratus was first described by the Swedish botanist Carl Linnaeus in 1753.^[3] Linnaeus based his diagnosis on a specimen collected along a riverbank in North America ("habitat in America ad fluviorum ripas").^[13]

As of October 2025^[update], the following infraspecific names are accepted by both Plants of the World Online and World Flora Online:^[4]^[14]

Cyperus odoratus subsp. odoratus
Cyperus odoratus subsp. transcaucasicus(Kük.) Kukkonen

The typical subspecies Cyperus odoratus subsp. odoratus has dozens of synonyms.^[5]Cyperus odoratus var. engelmannii(Steud.) R.Carter, S.D.Jones & Wipff is a homotypic synonym of Cyperus engelmanniiSteud. ^[15]

Cyperus odoratus is a member of Cyperus subgen. Diclidium(Schrad. ex Nees) C.B.Clarke.^[12] It is one of two species in subgenus Diclidium whose range extends into temperate North America (the other species being Cyperus engelmannii).

Distribution and habitat

Cyperus odoratus sensu lato is found in much of the tropical and warm temperate world, including South, Central, and North America, Southeast Asia, some Pacific Islands, Australia, New Guinea, Madagascar, and central Africa.^[4]^[8]^[16] It is a plant of wet, muddy areas, including disturbed and altered sites. Cyperus odoratus subsp. transcaucasicus is native to Iran, Iraq, and the South Caucasus.^[6]

References

↑ Bárrios, S.; Copeland, A. (2021). "Cyperus odoratus". The IUCN Red List of Threatened Species. Retrieved 26 October 2025.
↑ NatureServe (3 October 2025). "Cyperus odoratus". NatureServe Explorer. Arlington, Virginia. Retrieved 21 October 2025.
1 2 "Cyperus odoratusL.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 20 October 2025.
1 2 3 "Cyperus odoratusL.". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 20 October 2025.
1 2 "Cyperus odoratus subsp. odoratus". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 21 October 2025.
1 2 "Cyperus odoratus subsp. transcaucasicus(Kük.) Kukkonen". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 20 October 2025.
↑ Tucker, Gordon C. (2012). "Cyperus odoratus". Jepson eFlora. University and Jepson Herbaria. Retrieved 21 October 2025.
1 2 3 Tucker, Gordon C.; Marcks, Brian G.; Carter, J. Richard (2002). "Cyperus odoratus". 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 21 October 2025– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
↑ "Key to Cyperus". Flora of the Southeastern United States. Retrieved 22 October 2025.
↑ Standley (2025).
↑ Naczi (2017), p. 4.
1 2 Tucker & Gandhi (2019).
↑ Linnaeus (1753), pp. 46.
↑ "Cyperus odoratusL.". World Flora Online. Retrieved 22 October 2025.
↑ "Cyperus engelmanniiSteud.". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 3 November 2025.
↑ Dai, Lun-Kai; Tucker, Gordon C.; Simpson, David A. "Cyperus odoratus". Flora of China. Vol. 23. Retrieved 21 October 2025– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

Bibliography

Linnaeus, Carl (1753). Species Plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas (1st ed.). Stockholm: Impensis Laurentii Salvii. Retrieved 20 October 2025.
Naczi, R.F.C. (2017). "Portion of Cyperaceae, the sedge family: Cyperus". In Naczi, R.F.C.; Abbott, J.R.; and collaborators (eds.). New Manual of Vascular Plants of Northeastern United States and Adjacent Canada, compiled in 2016, 2017. Bronx, NY: New York Botanical Garden Press.
Standley, Lisa A. (2025). "Cyperus engelmannii in New England". Rhodora. 126 (1006): 178–182. doi:10.3119/25-08.
Tucker, Gordon C.; Gandhi, Kanchi N. (2019). "Nomenclatural notes on Cyperus odoratus and related species (Cyperaceae)". Harvard Papers in Botany. 24 (2): 349–357. doi:10.3100/hpib.v24iss2.2019.n18. ISSN 1938-2944.

External links

"Cyperus odoratus". Lady Bird Johnson Wildflower Center. University of Texas at Austin. Retrieved 24 October 2025.
"flat sedge (Cyperus odoratus)" (video). youtube.com. UF/IFAS Center for Aquatic and Invasive Plants. Retrieved 24 October 2025.
"Photos of Cyperus odoratus". CalPhotos. University of California, Berkeley. Retrieved 24 October 2025.
"Search for 'Cyperus odoratus'". International Plant Names Index (IPNI). Retrieved 24 October 2025.
"Treatment from the Jepson Manual (archived)". University and Jepson Herbaria. 1993. Retrieved 21 October 2025.

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[IUCN-1] Bárrios, S.; Copeland, A. (2021). "Cyperus odoratus". The IUCN Red List of Threatened Species. Retrieved 26 October 2025.

[NatureServe-2] NatureServe (3 October 2025). "Cyperus odoratus". NatureServe Explorer. Arlington, Virginia. Retrieved 21 October 2025.

[IPNI:74939-2-3] 1 2 "Cyperus odoratusL.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens . Retrieved 20 October 2025.

[POWO:74939-2-4] 1 2 3 "Cyperus odoratusL.". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 20 October 2025.

[POWO:77171060-1-5] 1 2 "Cyperus odoratus subsp. odoratus". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 21 October 2025.

[POWO:985955-1-6] 1 2 "Cyperus odoratus subsp. transcaucasicus(Kük.) Kukkonen". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 20 October 2025.

[ucjeps-7] Tucker, Gordon C. (2012). "Cyperus odoratus". Jepson eFlora. University and Jepson Herbaria. Retrieved 21 October 2025.

[FNA-8] 1 2 3 Tucker, Gordon C.; Marcks, Brian G.; Carter, J. Richard (2002). "Cyperus odoratus". 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 21 October 2025– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

[FSUS-9] "Key to Cyperus". Flora of the Southeastern United States. Retrieved 22 October 2025.

[FOOTNOTEStandley2025-10] Standley (2025).

[FOOTNOTENaczi20174-11] Naczi (2017), p. 4.

[FOOTNOTETuckerGandhi2019-12] 1 2 Tucker & Gandhi (2019).

[FOOTNOTELinnaeus1753[httpswwwbiodiversitylibraryorgpage358071page58mode1up_pp.&nbsp;46]-13] Linnaeus (1753), pp. 46.

[wfo-0000378607-14] "Cyperus odoratusL.". World Flora Online. Retrieved 22 October 2025.

[POWO:309322-2-15] "Cyperus engelmanniiSteud.". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 3 November 2025.

[FoC-16] Dai, Lun-Kai; Tucker, Gordon C.; Simpson, David A. "Cyperus odoratus". Flora of China. Vol. 23. Retrieved 21 October 2025– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

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