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Cyperaceae

"Sedge" redirects here. For other uses, see Sedge (disambiguation).

Cyperaceae
Temporal range: Eocene – Recent
Cyperus polystachyos flower head
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Cyperaceae
Juss.[1]
Genera

94, see text[2]

The Cyperaceae (/ˌsaɪpəˈreɪsi.iː, -ˌaɪ/) are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large; botanists have described some 5,500 known species in about 90 genera[3][4] – the largest being the "true sedges" (genus Carex),[5][6] with over 2,000 species.[7]

Distribution

Totora made artificial floating island communities of the Uru peoples in Lake Titicaca

Cyperaceae species are widely distributed, with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges grow in almost all environments, many thrive in wetlands, or in poor soils. Ecological communities dominated by sedges are known as sedgelands or as sedge meadows.

Classification

Some species superficially resemble the closely related rushes and the more distantly related grasses. Features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections (with occasional exceptions, a notable example being the tule which has a round cross-section) and leaves that are spirally arranged in three ranks. In comparison, grasses have alternate leaves, forming two ranks.[8][9] This leads to the mnemonic "sedges have edges," in order to tell them apart from generally round rushes or hollow, nodded grasses.[10][11]

Some well-known sedges include the water chestnut (Eleocharis dulcis) and the papyrus sedge (Cyperus papyrus), from which the writing material papyrus was made. This family also includes cotton-grass (Eriophorum), spike-rush (Eleocharis), sawgrass (Cladium), nutsedge or nutgrass (also called chufa, Cyperus esculentus/Cyperus rotundus, a cultivated crop and common weed), white star sedge (Rhynchospora colorata), and umbrella sedge (Cyperus alternifolius), also known as umbrella papyrus

Features

Members of this family are characterised by the formation of dauciform (carrot-like) roots; an alteration in root morphology that researchers regard as analogous to cluster roots in Proteaceae, which help uptake of nutrients such as phosphorus from poor soil.[12] Like other members of the order Poales, sedges are mostly wind-pollinated, but there are exceptions. Cyperus niveus and Cyperus sphaerocephalus, both with accordingly more conspicuous flowers, are insect-pollinated.[13]

Evolution

Researchers have identified sedges occurring at least as early as the Eocene epoch.[14]

Genera

As of 2024, 93 genera are accepted by Kew's Plants of the World Online.[2]

References

  1. ^ Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. hdl:10654/18083.
  2. ^ a b "Cyperaceae". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 22 August 2024.
  3. ^ Christenhusz, M. J. M.; Byng, J. W. (2016). "The number of known plants species in the world and its annual increase". Phytotaxa. 261 (3). Magnolia Press: 201–217. doi:10.11646/phytotaxa.261.3.1. Archived from the original on 29 July 2016. Retrieved 14 July 2016.
  4. ^ R. Govaerts; D. A. Simpson; with J. Bruhl; T. Egorova; P. Goetghebeur; K. Wilson (2007). Word Checklist of Cyperaceae: Sedges. Royal Botanic Gardens, Kew. ISBN 978-1-84246-199-0.
  5. ^ "sedge family". Merriam-Webster. Archived from the original on 26 December 2013. Retrieved 25 December 2013.
  6. ^ Milne, Lorus Johnson; Milne, Margery Joan Greene (1975). Living plants of the world. Random House. p. 301.
  7. ^ Hipp, Andrew L. (2007). "Nonuniform processes of chromosome evolution in sedges (Carex: Cyperaceae)". Evolution. 61 (9): 2175–2194. doi:10.1111/j.1558-5646.2007.00183.x. ISSN 0014-3820. PMID 17767589. S2CID 19514206.
  8. ^ "Grasslike non-grasses". Backyard Nature. Archived from the original on 5 March 2009. Retrieved 30 December 2014.
  9. ^ Ball, Peter W.; Reznicek, A. A.; Murray, David F. (2002). "Cyperaceae". 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 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  10. ^ "Telling apart grasses, sedges, rushes | Grasses at a Glance | Illinois Extension | UIUC". extension.illinois.edu. 17 April 2023. Retrieved 2 November 2024.
  11. ^ "Sedges Have Edges . . . (Grasses, Sedges & Rushes)". www.hiltonpond.org. Retrieved 2 November 2024.
  12. ^ Shane, Michael W.; Cawthray, Gregory R.; Cramer, Michael D.; Kuo, John; Lambers, Hans (2006). "Specialized 'dauciform' roots of Cyperaceae are structurally distinct, but functionally analogous with 'cluster' roots". Plant, Cell & Environment. 29 (10): 1989–1999. doi:10.1111/j.1365-3040.2006.01574.x. ISSN 0140-7791. PMID 16930324.
  13. ^ Wragg, Peter D.; Johnson, Steven D. (September 2011). "Transition from wind pollination to insect pollination in sedges: experimental evidence and functional traits". New Phytologist. 191 (4): 1128–1140. doi:10.1111/j.1469-8137.2011.03762.x. ISSN 0028-646X. PMID 21585389.
  14. ^ Shribbs, John (2021). "Sedges in our wetlands". Petaluma Wetlands Alliance. Retrieved 21 February 2024. Fossil sedges are known from as early as the Eocene 56 to 33.9 million years ago (mya) and modern sedges are very similar to ancient fossils.
Quelle: http://en.wikipedia.org/wiki/Cyperaceae