The Cyperaceae () are a family of

graminoid In botany and ecology, a graminoid refers to a herbaceous plant with a grass-like morphology, i.e., elongated culms with long, blade-like leaves. They are contrasted with forbs, herbaceous plants without grass-like features. The plants most ...

(grass-like),

monocotyledon Monocotyledons (), commonly referred to as monocots, ( Lilianae '' sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks ...

ous flowering plants known as

sedges The Cyperaceae () 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 generathe largest being the "true sedges" (genu ...

. The

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

is large; botanists have described some 5,500 known species in about 90

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

the largest being the "true

" (genus ''

Carex ''Carex'' is a vast genus of over 2,000 species of grass-like plants in the family (biology), family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those of ge ...

''), with over 2,000 species.

Distribution

Cyperaceae species are widely distributed with the centers of diversity for the group occurring in

tropic The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

and tropical

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. While sedges grow in almost all environments, many thrive in

wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

or in poor soils.

Ecological communities In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community ...

dominated by sedges are known as s or as

sedge meadow A hydrosere is a plant succession which occurs in an area of fresh water such as in oxbow lakes and kettle lakes. In time, an area of open freshwater will naturally dry out, ultimately becoming woodland. During this change, a range of different la ...

Classification

Some species superficially resemble the closely related rushes and the more distantly related

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

es. 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 ''Schoenoplectus acutus'' ( syn. ''Scirpus acutus, Schoenoplectus lacustris, Scirpus lacustris'' subsp. ''acutus''), called tule , common tule, hardstem tule, tule rush, hardstem bulrush, or viscid bulrush, is a giant species of sedge in the p ...

that has a round cross-section) and leaves that are spirally arranged in three

ranks A rank is a position in a hierarchy. It can be formally recognized—for example, cardinal, chief executive officer, general, professor—or unofficial. People Formal ranks * Academic rank * Corporate title * Diplomatic rank * Hierarchy ...

. In comparison, grasses have alternate leaves, forming two ranks. This difference leads to the mnemonic "sedges have edges" in order to tell them apart from generally round rushes or hollow, nodded

grasses Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and species cultivated in ...

. Some well-known sedges include the water chestnut (''

Eleocharis dulcis ''Eleocharis dulcis'', the Chinese water chestnut or water chestnut, is a grass-like Cyperaceae, sedge native to Asia, tropical Africa, and Oceania. It is grown in many countries for its edible corms, but if eaten uncooked, the surface of the ...

'') and the papyrus sedge (''

Cyperus papyrus ''Cyperus papyrus'', better known by the common names papyrus, papyrus sedge, paper reed, Indian matting plant, or Nile grass, is a species of aquatic plant, aquatic flowering plant belonging to the sedge family Cyperaceae. It is a Hardiness (pla ...

''), from which the writing material

papyrus Papyrus ( ) is a material similar to thick paper that was used in ancient times as a writing surface. It was made from the pith of the papyrus plant, ''Cyperus papyrus'', a wetland sedge. ''Papyrus'' (plural: ''papyri'' or ''papyruses'') can a ...

was made. This family also includes cotton-grass (''

Eriophorum ''Eriophorum'' (cottongrass, cotton-grass or cottonsedge) is a genus of flowering plants in the family Cyperaceae, the sedge family. They are found in the cool temperate, alpine, and Arctic regions of the Northern Hemisphere, primarily in the mi ...

''), spike-rush (''

Eleocharis ''Eleocharis'' is a virtually cosmopolitan genus of 250 or more species of flowering plants in the sedge family, Cyperaceae. The name is derived from the Greek words ἕλειος (''heleios''), meaning "marsh dweller," and χάρις (''charis'' ...

''), sawgrass (''

Cladium ''Cladium'' (fen-sedge, sawgrass or twig-sedge) is a genus of large sedges, with a nearly worldwide distribution in tropical and temperate regions. These are plants characterized by long, narrow (grass-like) leaves having sharp, often serrated ( ...

''), nutsedge or nutgrass (also called chufa, ''

Cyperus esculentus ''Cyperus esculentus'' (also called chufa, tiger nut, atadwe, yellow nutsedge, earth almond, and in Chishona, pfende) is a species of plant in the sedge family widespread across much of the world. It is found in most of the Eastern Hemisphere, i ...

''/''

Cyperus rotundus ''Cyperus'' is a large genus of about 700 species of sedges, distributed throughout all continents in both tropical and temperate regions. Description They are annual or perennial plants, mostly aquatic and growing in still or slow-moving ...

'', a cultivated crop and common weed), white star sedge (''

Rhynchospora colorata ''Rhynchospora colorata'', also known as starrush whitetop, white star sedge and white-topped sedge, is a perennial flowering plant in the sedge family. It has white bracts, giving it the appearance of white petals with long, green points. It is ...

''), and umbrella sedge (''

Cyperus alternifolius ''Cyperus alternifolius'', the umbrella papyrus, umbrella sedge or umbrella palm, is a grass-like plant in the large genus ''Cyperus'' of the sedge family Cyperaceae. The plant is native to West Africa, Madagascar and the Arabian Peninsula, but w ...

''), also known as umbrella papyrus

Features

Members of this family are characterised by the formation of dauciform (carrot-like) roots that are an alteration in root morphology that researchers regard as analogous to

cluster root Cluster roots, also known as proteoid roots, are plant roots that form clusters of closely spaced short lateral rootlets. They may form a two- to five-centimetre-thick mat just beneath the leaf litter. They enhance nutrient uptake, possibly by che ...

s in

Proteaceae The Proteaceae form a family (biology), family of flowering plants predominantly distributed in the Southern Hemisphere. The family comprises 83 genus, genera with about 1,660 known species. Australia and South Africa have the greatest concentr ...

, which help uptake of nutrients such as

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

from poor soil. Like other members of the order Poales, sedges are mostly

wind-pollinated Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including Poaceae, grasses, Cyperaceae, sedges, and Juncaceae, rushes. ...

, but there are exceptions. '' Cyperus niveus'' and '' Cyperus sphaerocephalus,'' both with accordingly more conspicuous flowers, are insect-pollinated.

Evolution

Researchers have identified sedges occurring at least as early as the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

epoch.

Genera

, 93 genera are accepted by

Kew Kew () is a district in the London Borough of Richmond upon Thames. Its population at the 2011 census was 11,436. Kew is the location of the Royal Botanic Gardens ("Kew Gardens"), now a World Heritage Site, which includes Kew Palace. Kew is ...

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

References

External links

*
Cyperaceae
at th
''Angiosperm Phylogeny Website''
{{Authority control Poales families