The Cyperaceae (/spəˈrsiˌ, -sˌ/) 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]

Cyperus polystachyos flower head
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Cyperaceae

94, see text[2]

Distribution edit

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 edit

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][10]

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 (Cyperus rotundus, a common lawn weed), and white star sedge (Rhynchospora colorata).

Features edit

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.[11]

Evolution edit

Researchers have identified sedges occurring at least as early as the Eocene epoch.[12]

Genera edit

As of 2024, 94 genera are accepted in Kew's Plants of the World Online:[2]

References edit

  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. Archived from the original on 27 February 2020. Retrieved 11 February 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 – definition and more from the free Merriam-Webster Dictionary". 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, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  10. ^ Brian R. Speer (29 September 1995). "Glumiflorae: More on Morphology". University of California, Berkeley. Archived from the original on 6 May 2009. Retrieved 23 March 2007.
  11. ^ 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.
  12. ^ 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.

External links edit