Cyperus
Family :
Famille :
Cyperaceae
Synonym(s) :
Synonyme(s) :
Common Name(s) :
Nom(s) commun(s) :
Umbrella Sedge
(FNA 1993+)
Flat Sedge (FNA 1993+; GBIF 2024)
Nutsedge (Weed Gallery n.d.)
Cyperus esculentus (yellow nut sedge) achenes
Cyperus esculentus (yellow nut sedge) achenes
Cyperus esculentus (yellow nut sedge)achenes
Cyperus esculentus (yellow nut sedge) achene
Cyperus esculentus (yellow nut sedge) achene; cross section
Cyperus esculentus (yellow nut sedge) floral scale
Cyperus rotundus (purple nutsedge) achenes
Cyperus rotundus (purple nutsedge) achenes
Cyperus rotundus (purple nutsedge) achene
Cyperus rotundus (purple nutsedge) achene
Cyperus rotundus (purple nutsedge) achene; cross section
Cyperus rotundus (purple netsedge) close-up of the surface
Cyperus rotundus (purple netsedge) floral scale
Explore More :
Explore plus :
Overview
Aperçu
Regulation :
Remarques Réglementation:
Regulation Notes:
Distribution :
Répartition :
Cyperus is a large cosmopolitan genus of approximately 600 Cyperus species if considered in the strict sense (FNA 1993+), found throughout the temperate and tropical biomes, native to most countries on every continent except Antarctica (POWO 2024). Alternatively, there may be as much as 950 species if previously separated genera such as Pycreus and Kyllingia are included (FNA 1993+; Verloove 2014; POWO 2024). There are an estimated 43 species in Europe, with almost half being introduced (FNA 1993+; Verloove 2014). China contains approximately 62 Cyperus species, and Australia has over 150 species, 50 of which are endemic to the country (FOC 2024; PlantNET 2024).
In Canada, there are 18 species, including 3 introduced and 15 native species found in every province except Prince Edward Island and Newfoundland. No Cyperus are found in the northern Territories (Brouillet et al. 2010+).
In the USA, there are about 103 native species, 24 introduced species and one native hybrid (USDA NRCS 2024).
Cyperus rotundus is native to southern Europe, Africa, Asia and Australia, and has spread to North and South America (POWO 2024).
Varieties of Cyperus esculentus are native to Africa, the Mediterranean countries, India, Central Asia, North and South America, and have been introduced into Australia, southern and eastern Asia (De Castro et al. 2015).
Cyperus difformis is native to warm or tropical areas of southern Europe, Asia, Africa and the Pacific Islands, introduced into Central and North America (Holm et al. 1991).
Cyperus iria is native to Africa, Asia and Australia and introduced to Europe, southern North America and South America (Holm et al. 1991; POWO 2024).
Cyperus fuscus is native to a wide area in Europe, Asia, India and northern Africa, and has been introduced to the United States and Canada (Bryson and Carter 2010; POWO 2024).
Cyperus aromaticus, native to equatorial Africa and islands in the Indian Ocean, has spread aggressively into the Indian subcontinent, Malay Peninsula, Australia and the Pacific Islands (Shi et al. 2021).
Habitat and Crop Association :
Habitat et Cultures Associées :
Cyperus constitutes over 40% of weedy species in the Cyperaceae family of which C. rotundus L. and C. esculentus L. are the most widespread and well-studied species (Bendixon and Nandihalli 1987; Holm et al. 1991). Other important crop weeds include C. difformis L., C. iria L., C. fuscus L., and C. aromaticus (Ridl.) Mattf. & Kük. (synonym Kyllinga aromatica Ridl.) (Holm et al. 1991; Bryson and Carter 2010; Bryson and Carter 2012; Shi et al. 2021). Most Cyperus are naturally found primarily in or adjacent to wetland habitats, mostly restricted to soils with high moisture contents (personal observation).
Cyperus rotundus establishes in a wide range of soil types and moisture regimes, but does not grow well in shaded areas and waterlogged or saline soils (Holm et al. 1991). It can be found in cultivated fields, roadsides, waste areas, irrigation canals and edges of woods (Holm et al. 1991). C. rotundus is a perennial weed of 52 crops in 92 countries, most significantly in Gossypium hirsutum L. (cotton), Oryza sativa L. (rice); Zea mays L. subsp. mays (corn) and vegetables (Holm et al. 1991).
Cyperus esculentus has a larger geographic range than C. rotundus due to being more cold- and drought-tolerant, but is still limited by frost (Bendixon and Nandihalli 1987; Follak et al. 2016). The species grows well on all soil types and moisture regimes, tolerating a higher soil moisture than C. rotundus (Holm et al. 1991; Follak et al. 2016). C. esculentus can be found in moist fields, irrigated crops, riverbanks and roadsides, and may grow in mixed stands with C. rotundus (Holm et al. 1991). C. esculentus is a perennial weed of 21 crops in more than 30 countries, primarily Glycine max (L.) Merr. (soybeans); G. hirsutum, Saccharum officinale L. (sugarcane), Solanum tuberosum L. (potato) and Z. mays subsp. mays (Holm et al. 1991). It is a lesser known weed of Arachis hypogaea L. (peanuts), Beta vulgaris L. subsp. vulgaris (sugar beets), Coffea spp. (coffee) and O. sativa (Holm et al. 1991). C. esculentus has developed herbicide resistance to azimsulfuron and halosulfuron-methyl in Italy and the USA (HEAP 2024).
Cyperus difformis is primarily an annual weed of O. sativa but can also infest crops of Camellia sinensis (L.) Kuntze (tea), Musa spp. (banana), S. officinale and Z. mays subsp. mays (Holm et al. 1991). It also shows multiple herbicide resistances to azimsulfuron, bensulfuron-methyl, cinosulfuron, cyclosulfamuron, ethoxysulfuron, halosulfuron-methyl, imazosulfuron, and pyrazosulfuron-ethyl (HEAP 2024).
Cyperus iria is another important annual weed of O. sativa, but can also infest A. hypogaea, C. sinensis, G. max, Musa spp. and Z. mays subsp. mays crops (Holm et al. 1991). Cyperus fuscus is a third significant Cyperus weed of O. sativa, and will likely become problematic in O. sativa crops and natural wetlands in the southeastern United States (Bryson and Carter 2010). It has also developed resistance to bispyribac-sodium, imazapic, imazethapyr, penoxsulam, and pyrazosulfuron-ethyl (HEAP 2024).
Cyperus aromaticus is an aggressively spreading perennial weed in wet soils of pastures, roadsides and lawns where it is avoided by cattle unless no other feed is available (Shi et al. 2021). The species infests fields of Musa acuminata Colla (banana), Ipomoea batatas L. (sweet potato) and S. officinarum crops within Australia (Shi et al. 2021).
Cyperus odoratus L. is also a pest of O. sativa crops in Venezuela, showing resistance to the herbicide pyrazosulfuron-ethyl (HEAP 2024).
It has been reported that Cyperus species have a strong allelopathic effect in many crops where extracts significantly reduced the dry weight of numerous crops (Zhang et al. 2022). However, given their preference for wetland habitats, Cyperus species are most problematic agricultural pests of Oryza sativa (rice) crops due to their aquatic cultivation methods, but they can also be problematic in heavily irrigated or poorly draining agricultural soils and irrigation ditches (Zhang et al. 2022).
Economic Use, cultivation area, and Weed Association :
Utilisation économique, zone de culture et association de mauvaises herbes :
Numerous Cyperus species have been used in traditional medicines for gastrointestinal, respiratory, and blood disorders (Taheri et al. 2021). They contain a wide variety of bioactive compounds that may possess antioxidant, anti-inflammatory, antimicrobial, anticancer, neuroprotective, anti-depressive, anti-arthritic, anti-obesity, vasodilator, spasmolytic, bronchodilator, and estrogenic properties (Taheri et al. 2021).
They are also used as food; for example, Cyperus esculentus L., known commonly as the Tiger Nut, is cultivated for its tuberous roots throughout Southern Europe, North Africa and West Africa, and increasingly in China and the Americas (Zhang et al. 2022).
Cyperus esculentus is a nutritious food source rich in protein, starch, dietary fibre, vitamins, and essential nutrients (Zhang et al. 2022). The global tiger nut market was $153 million in 2020, and the market is growing and is expected to reach $319 million by 2030 (Transparency Market Research 2021).
Cyperus bulbosus Vahl is an important bush food of the Kimberley Aboriginal people in Australia (SKIPA 2012). In North America, Cyperus species have been eaten and used for medicine and cordage by numerous indigenous peoples (NAEB 2019). They were such an important food source for the Pauites people that they were referred to as tövusi-dökadö, meaning “nutsedge tuber eaters” (Hittman 1996).
Cyperus articulatus L. is known as priprioca in Brazil, where it is used medicinally, as a food flavouring, and in the cosmetic industry (Atala 2012).
Most information available on weed association concerns Cyperus as a weed of other crops. However, studies done in Ontario showed while there was no change in yield with irrigation or fertilizer additions, there was an 844% increase in yields when a critical weed-free period of 3 weeks was used (Elford et al. 2021), although no mention was made of which weeds were being removed. In the United States, Amaranthus hybridus L., Digitaria sanguinalis (L.) Scop., Galinsoga quadriradiata Ruiz & Pav. and Mollugo verticillata L. were reported as common field weeds of C. esculentus var. sativus (Besançon et al. 2021). There are concerns that crops may cross-pollinate with weedy C. esculentus in the field, but C. esculentus var. sativus has been reported to rarely flower (Ayeni 2022).
Duration of Life Cycle :
Durée du cycle vital:
Perennial or annual
Dispersal Unit Type :
Type d’unité de dispersion :
Achenes, tubers (vegetative)
Distribution of Cyperus L. spp. in Canada and the United States (source: USDA-NRCS 2025)
Global distribution of Cyperus L. spp. (source: GBIF 2025)
General Information
RENSEIGNEMENTS GÉNÉRAUX
All Cyperus species invasive in O. sativa crops are also considered invasive outside of agriculture. In addition to the species mentioned above, Cyperus entrerianus Boeckeler can invade wet, undisturbed natural habitats and roadside ditches, forming monocultures and displacing native vegetation and spreads mostly via human activities (Swearingen and Bargeron 2016). Often, at least in North America, invasive Cyperus species do not reproduce by fruit or seed and instead spread vegetatively via their tuberous roots (Weed Gallery n.d.), often erroneously referred to as ‘nutlets,’ not to be confused with the fruit by the same name.
The perennials Cyperus rotundus and C. esculentus proliferate by underground stems (rhizomes) that produce tubers and new plants (Holm et al. 1991). In the United States, Tumbleson and Kommedahl (1961) found that each C. esculentus plant produced 7-9 tubers, and each tuber could produce 1900 plants plus 7000 tubers and cover a 6.5 foot area in one year. In India, it was found that one tuber of C. rotundus could produce 99 tubers in 90 days, which would result in 8 million tubers per hectare of cultivated land and 4.8 million in uncultivated areas (Holm et al. 1991).
Several Cyperus species are nuisance pests found in irrigated lawns (personal observation).
The first paper product, papyrus, was made from Cyperus papyrus L. in ancient Egypt (Taheri et al. 2021).
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Cyperus esculentus infestation (yellow leaves) in a lawn. (Doug Doohan, Ohio State University/ OARDC, Bugwood.org)
Identification
Identification
-
Achene
Size
- Cyperus esculentus achene length*: 1.1-1.6 mm; width: 0.6-0.8 mm
*Note: minimum and maximum based on 10 achenes in normal range of this species using image measurement protocol (ISMA 2020).
Achene sizes from literature:
Cyperus subg. Cyperus
Cyperus esculentus L.
• Achene length: (1.1–)1.3–1.5(–1.6) mm; width: 0.3–0.6(–0.8) mm (FNA 1993+)
• Achene length: 1.5-1.7; width: 0.6-0.8 mm (Bojňanský and Fargašová 2007)Cyperus iria L.
• Achene length: 1.2–1.4 mm; width: 0.5–0.7 mm (FNA 1993+)Cyperus rotundus L.
• Achene length: 1.5 mm; width: 0.8 mm (Holm et al. 1991)
• Achene length: 1.4–1.7(–1.9) mm; width: 0.8–1 mm (FNA 1993+)Cyperus schweinitzii Torr. (example of large achene)
• Achene length: 2–2.4 mm; width: 0.9–1.4 mm (FNA 1993+)Cyperus subg. Diclidium (Schrad. ex Nees) C. B. Clarke
Cyperus odoratus L.
• Achene length: (1–)1.2–1.5(–1.9) mm; width: 0.5–0.6(–0.75) mm (FNA 1993+)Cyperus subg. Juncellus (Grisebach) C. B. Clarke
Cyperus serotinus Rottb.
• Achene length: 1.4–1.6 mm; width: 1.4–1.5 mm (FNA 1993+)
• Achene length: 1.5-1.7 mm; width: 1.2-1.3 mm (Bojňanský and Fargašová 2007)Cyperus subg. Pycreus (Palisot de Beauvois) J. Carey
Cyperus flavescens L.
• Achene length: 1–1.2 mm; width: 0.8 mm (FNA 1993+)
• Achene length: 0.9-1.1 mm; width: 0.7 mm (Bojňanský and Fargašová 2007)Cyperus subg. Pycnostachys C. B. Clarke
Cyperus difformis L. (example of small achene)
• Achene length: 0.6–0.8 mm; width: 0.3–0.4 mm (FNA 1993+)
• Achene length: 0.6-0.7 mm; width: 0.3-0.35 mm (Bojňanský and Fargašová 2007)Cyperus fuscus L.
• Achene length: 0.7–0.9 mm; width: 0.4 mm (FNA 1993+)
• Achene length: 1-1.1; width: 0.4-0.5 mm (Bojňanský and Fargašová 2007)Shape
- Achenes of subgenus Cyperus are generally oval or oblong shaped with a peg-like style remnant at one end, trigonous in 3D
- Achenes from the subgenera Pycnostachys and Diclidium are generally oval or long egg-shaped with a peg-like style remnant at one end and a prominent, flared attachment point at the opposite end, trigonous, planoconvex or terete in 3D
- Achenes of subgenus Pycreus and Juncellus are generally broad oval or egg-shaped with a style remnant at one end and a short attachment point at the other, biconvex in 3D.
Surface Texture
- Achenes generally have a bubbled, papillate tuberculate, stippled or ridged reticulate surface
Colour
- Achenes are light brown, yellowish, dark brown or black coloured
Other Features
- Achenes may have 1-3 long stamen remnants attached to the end opposite the style remnant
- The remnant stamens are thin, flattened and without bristles or hairs
- The persistent, yellow-brown, bubbled outer layer of C. esculentus achenes can be scraped off, revealing a reddish, ridged reticulate surface beneath
Cyperus esculentus (yellow nut sedge) achenes
-
Tuber
Size
- Tuber sizes from literature:
Cyperus esculentus L.
• Tuber diameter: 3-11 mm (Tumbleson and Kommendahl 1979)Cyperus rotundus L.
• Tuber length: 1-1.5 cm; width: 0.5-1 cm (Holm et al. 1991)Shape
- Cyperus esculentus tubers are generally round or oval, some are elongated oval with a peg-like rhizome remnant at one end and a tuft of fibrous strands at the other
- C. rotundus tubers are generally elongated oval or cylindrical with rhizome remnants at both ends
Surface Texture
- Tubers have several thin, transverse ridges that become pronounced when dried
- Tuber surface generally smooth or roughened
Colour
- Cyperus esculentus tubers are generally yellowish brown
- C. rotundus tubers are generally dark brown or purplish coloured
Other Features
- Cyperus tubers are dense, and become very hard and difficult to cut when dried
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Seed
Size
- Seed fills the achene; seed size similar to achene size
Shape
- Seeds are oval, oblong or egg-shaped
Surface Texture
- Seed surface is roughened
Colour
- Seeds are generally yellowish brown
-
Embryo
Size
- Embryo size varies from rudimentary to partially filling the seed (Martin 1946)
Shape
- Embryo is linear shaped, generally with one wide end (capitate shaped) (Martin 1946)
Endosperm
- Endosperm is granular or firm, and translucent white coloured (Martin 1946)
Other Features
- Embryo is in a basal potion in the seed
Cyperus esculentus (yellow nut sedge) achene; cross section
Identification Tips
CONSEILS POUR L’IDENTIFICATION
The generally oval-shaped, biconvex or trigonous Cyperus achenes with a peg-like style remnant and attachment point at opposite ends appear similar to achenes in other Cyperaceae genera such as Carex and Eleocharis.
Features that can be used to recognize and distinguish achenes of Cyperus include:
- Achenes are held in, and disperse from scale-like bracts arranged into spikelets
- Bracts do not enclose the achene as in Carex perigynia
- Oval, elongated egg-shaped or oblong achenes with peg-like style remnant and attachment point at opposite ends
- Generally trigonous or biconvex in 3 dimensions
- Surface rarely smooth, generally bubbled, papillate tuberculate or stippled
- Attachment point of achene may have 1-3 narrow, strap-like stamen remnants without bristles or hairs
- Cyperus achenes do not have perianth remnants, unlike in Eleocharis, Schoenoplectus or Scirpus with up to 8 strap-like, bristle-edged perianth segments or in Eriophorum with 10 or more long, hair-like segments
Cyperus esculentus (yellow nut sedge) achene
Additional Botany Information
AUTRES RENSEIGNEMENTS BOTANIQUES
Flowers/Inflorescence
- Inflorescences are mostly at the top of stems, rarely on the sides; 1st-order inflorescences are umbel-like or in heads at the ray tips; 2nd-order are spike-like or with 3 or more spikelets from the same node, rarely are they solitary (FNA 1993+).
- Spikelets 1–150; 1st-order rays nearly always unequal in length, arising singly from the axils of inflorescence bracts (FNA 1993+).
- Involucral bracts are leaf-like; 1–22; spirally arranged at the tip of the stem beneath the base of the inflorescence, spreading to erect (FNA 1993+; WFO 2024). The bracts are often confused with leaves since they look like leaves and can be up to 15cm or longer.
- Spikelets with up to 76 scales in 2 opposite alternately arranged rows, each subtending a flower (FNA 1993+), but the bottom ones may not have associated flowers (WFO 2024).
- Flowers are mostly bisexual, very rarely unisexual, borne in axils of scales; bases often extending downward onto rachilla as wings; no perianth is present; stamens 1–3; styles linear, 2–3 times dissected; stigmas 2–3 (FNA 1993+).
- The presence of bisexual flowers without any paper-like sacs surrounding them differentiates Cyperus from the closely related but mostly monoecious Carex.
Vegetative Features
- Perennial herbs, occasionally annual; from rhizomes, stolons, or occasionally tubers (FNA 1993+); though many sources refer to them all as tuberous roots.
- In the tuber-bearing Cyperus esculentus and C. rotundus, stems arise from a basal bulb that sends out rhizomes that produce either new stems or a tuber (Holm et al. 1991). These tubers will sprout stems, or in C. rotundus, produce either stems or another tuber (Holm et al. 1991).
- Stems are simple and may be solitary or in clusters; usually three-sided (trigonous) (WFO 2024) or sometimes round in cross-section; hairless or very minutely rough-hairy (FNA 1993+).
- Leaves are mostly basal, 3-ranked (WFO 2024); ligules are absent; blades are keeled on lower surfaces and flat, V-shaped, or inversely W-shaped in cross-section (FNA 1993+).
- The presence of three-sided and unjointed stems helps differentiate all sedges (Cyperaceae) from the related grass family (Poaceae). “Sedges have edges and grasses have knees” is an easy way to remember this.
Cyperus odoratus inflorescence before achenes have matured from Plymouth, Indiana, USA. (Lyrae Willis, Environmental Science Freelance Writer, lyraenatureblog.com)
Similar Species
ESPÈCES SEMBLABLES
Similar species are based on a study of seed morphology of various species, and those with similar dispersal units are identified. The study is limited by physical specimen and literature availability at the time of examination, and possibly impacted by the subjectivity of the authors based on their knowledge and experience. Providing similar species information for seed identification is to make users aware of similarities that could possibly result in misidentification.
Carex L. species
The achenes of Carex are shed enclosed in a fused bract called the perigynia, compared to achenes shed without an attached bract. Carex achenes removed from the perigynia are generally larger than Cyperus achenes, e.g. Carex aquatilis achene length: 2–3.6 mm; width: 1.3–2.3 mm, compared to Cyperus rotundus achene length: 1.4–1.7(–1.9) mm; width: 0.8–1 mm (FNA 1993+). Carex achenes may have a longer style remnant than Cyperus achenes (e.g. Carex lurida) and lack a peg-like attachment point opposite the style. Carex achenes will also not have persistent stamen remnants on the attachment point.
Eleocharis R. Brown species
Eleocharis achenes can be a similar size as Cyperus achenes, but are generally egg-shaped to almost triangular and biconvex or planoconvex in 3 dimensions, rarely trigonous. The achenes generally have a smooth surface and the style expanded into a spongy tubercle that may be as wide as the achene, compared to the rough surface and peg-like style of Cyperus achenes. There are persistent perianth bristles on the attachment point of Eleocharis achenes, and are toothed along the edges.
Click to select species
Cliquez pour sélectionner les espèces
Carex rostrata
Carex tristachya
Eleocharis tenuis
Eleocharis palustris
Eleocharis engelmannii
Eleocharis obtusa
Comparison Window
Fenêtre de comparaison
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus esculentus (yellow nut sedge) achenes
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus esculentus (yellow nut sedge)achenes
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus esculentus (yellow nut sedge) achene
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus esculentus (yellow nut sedge) achene; cross section
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus esculentus (yellow nut sedge) floral scale
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple nutsedge) achenes
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple nutsedge) achenes
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple nutsedge) achene
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple nutsedge) achene
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple nutsedge) achene; cross section
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple netsedge) close-up of the surface
MAIN SPECIES
ESPÈCES PRINCIPALES
Cyperus
Cyperus
Cyperaceae
Cyperus rotundus (purple netsedge) floral scale
SIMILAR SPECIES
ESPÈCES SEMBLABLES
Carex rostrata
Carex rostrata
Cyperaceae
Sedge (Carex rostrata) perigynia
SIMILAR SPECIES
ESPÈCES SEMBLABLES
Carex rostrata
Carex rostrata
Cyperaceae
Sedge (Carex rostrata) perigynium
SIMILAR SPECIES
ESPÈCES SEMBLABLES
Carex rostrata
Carex rostrata
Cyperaceae
Sedge (Carex rostrata) perigynium
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Reference(s)
Référence(s)
Atala, A. 2012. A new ingredient: The introduction of priprioca in gastronomy. International Journal of Gastronomy and Food Science, 1(1), 61-63. https://doi.org/10.1016/j.ijgfs.2011.11.001
Ayeni, A.O. 2022. Hoop house and field evaluation of tigernut (Cyperus esculentus L. var. sativus Boeck) selections in New Jersey, USA. Plants 11, 897. https://doi.org/10.3390/plants11070897
Bendixon, L.E. and Nandihalli, U.B. 1987. Worldwide distribution of purple and yellow nutsedge (Cyperus rotundus and C. esculentus). Weed Technology 1: 61-65.
Besançon, T.E., Carr, B.L., and Ayeni, A. 2021. Weed control and tigernut response to preemergence herbicides applied at transplanting. HortTechnology 34: 514-523.
Brouillet L., Desmet P., Coursol F., Meades S.J., Favreau M., Anions M., Bélisle P., Gendreau C., Shorthouse D., (2010+). Database of Vascular Plants of Canada (VASCAN). Online at http://data.canadensys.net/vascan Accessed March 5, 2024.
Bryson, C.T. and Carter, L. 2010. Spread, growth parameters, and reproductive potential for brown flatsedge (Cyperus fuscus). Invasive Plant Science and Management 3:240–245.
De Castro, O., Gargiulo, R., Del Guacchio, E., Caputo, P. and De Luca, P. 2015. A molecular survey concerning the origin of Cyperus esculentus (Cyperaceae, Poales): two sides of the same coin (weed vs. crop). Annals of Botany 115: 733–745.
Elford, E., Todd, J., White, P., Riddle, R., O’Sullivan, J., & Van Acker, R. 2021. Cultural Management Practices for Commercial Tigernut Production in Southern Ontario, Canada. HortTechnology hortte, 31(1), 14-18. https://doi.org/10.21273/HORTTECH04682-20
Flora of North America (FNA) Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York and Oxford. http://beta.floranorthamerica.org Accessed September 12, 2024.
Follak, S., Belz, R., Bohren, C., De Castro, O., Del Guacchio, E., Pascual-Seva, N., Schwarz, M., Verloove, F. and Essl, F. 2016. Biological flora of Central Europe: Cyperus esculentus L. Perspectives in Plant Ecology, Evolution and Systematics 23: 33–51.
Global Biodiversity Information Facility (GBIF) Secretariat. 2024. https://www.gbif.org Accessed March 5, 2024.
Heap, I. 2024. The International Herbicide-Resistant Weed Database. Online. Available www.weedscience.org Accessed March 5, 2024.
Hittman, Michael. 1996. Corbett Mack: The Life of a Northern Paiute. U of Nebraska Press. pp. 274–275. ISBN 9780803223769.
Holm, L. G., Plucknett, D. L., Pancho, J. V. and Herberger, J. P. 1991. The World’s Worst Weeds, Distribution and Biology. Krieger Publishing, Florida. 609 pp.
International Seed Morphology Association (ISMA). 2020. Method for Seed Size Measurement. Version 1.0. ISMA Publication Guide.
Martin, A.C. 1946. The comparative internal morphology of seeds. The American Midland Naturalist 36: 513-660.
Native American Ethnobotany Database (NAEB). 2019. Brit.org. http://naeb.brit.org
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