''Eleocharis'' is a virtually cosmopolitan genus of 250 or more species of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...
s in the sedge family,
Cyperaceae
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus '' Carex'' ...
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
words ἕλειος (''heleios''), meaning "marsh dweller," and χάρις (''charis''), meaning "grace." Members of the genus are known commonly as spikerushes or spikesedges. The genus has a geographically cosmopolitan distribution, with centers of diversity in the Amazon Rainforest and adjacent eastern slopes of the
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...
n
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...
,
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number ...
, and subtropical
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...
. The vast majority of ''Eleocharis'' species grow in aquatic or mesic habitats from sea level to higher than 5,000 meters in elevation (in the tropical Andes).
The genus itself is relatively easy to recognize; all ''Eleocharis'' species have photosynthetic stems but no green leaves (the leaves have been reduced to sheaths surrounding the base of the stems). Many species are robust, rhizomatously-spreading plants of lowland tropical
wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...
s, while many others are small
caespitose
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...
annual or perennial herbs growing near streams, and still others are intermediate. There are also a number of species that are obligate aquatic species, which usually have submerged, branching stems and often exhibit interesting photosynthetic adaptations, such as the ability to switch between C3 and C4 carbon fixation in response to different environmental stimuli. In all ''Eleocharis'' species, the flowers are borne on unbranched terminal spikelets at the apices of stems.Biota of North America Program, 2013 county distribution maps for US and Canadian species /ref>
In spite of the diversity of the genus itself, taxonomic characters useful for delimiting species within it are few, and many species are very difficult to tell apart. Many currently recognized species with very wide geographic ranges are highly polymorphic. Some of these species probably contain multiple independently evolving lineages. Because of their difficult nature, it is suggested that many botanists avoid collecting these plants and so many species are under-represented in the botanical record.
One of the best known species is the Chinese water chestnut, ''
Eleocharis dulcis
''Eleocharis dulcis'', the Chinese water chestnut or water chestnut, is a grass-like sedge native to Asia, tropical Africa, and Oceania. It is grown in many countries for its edible corms.
The water chestnut is not a nut, but an aquatic ve ...
''. These plants bear tubers on their rhizomes which may be peeled and eaten raw or boiled. In Australia,
magpie geese
The magpie goose (''Anseranas semipalmata'') is the sole living representative species of the family Anseranatidae. This common waterbird is found in northern Australia and southern New Guinea. As the species is prone to wandering, especially ...
rely almost exclusively on these tubers for sustenance for a significant portion of the year.
Eleocharis confervoides
''Eleocharis confervoides'' is a species of plant in the sedge family (Cyperaceae). It is a perennial, submerged, aquatic and deeply rooted herb. It is known by its common name Algal bulrushEleocharis congesta'' D.Don
*''
Eleocharis cylindrostachys
''Eleocharis cylindrostachys'' is a rush type plant growing in dense clumps from 40 to 60 cm tall. Found growing in moist situations in New South Wales and Queensland, Australia. The specific epithet ''cylindrostachys'' is derived from Latin and ...
Eleocharis dulcis
''Eleocharis dulcis'', the Chinese water chestnut or water chestnut, is a grass-like sedge native to Asia, tropical Africa, and Oceania. It is grown in many countries for its edible corms.
The water chestnut is not a nut, but an aquatic ve ...
Eleocharis erythropoda
''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' ...
Eleocharis geniculata
''Eleocharis geniculata'' is a species of spikesedge known by several common names, including bent spikerush and Canada spikesedge. This is a widespread plant of wet areas in the Americas, Asia, Africa, Australia, Madagascar, and some Pacific Is ...
'' (L.) Roem. & Schult. – Canada spikesedge
*''
Eleocharis gracilis
''Eleocharis gracilis'' the slender spike rush is a slender rush type plant growing from 20 to 50 cm tall, rarely up to a metre tall. Found in small clumps, growing in seasonally moist situations in many parts of south eastern Australia and ...
'' R.Br.
*''
Eleocharis halophila
''Eleocharis halophila'', the saltmarsh spikerush, is a perennial halophytic plant endemic to salt marshes in eastern Canada, in Ontario in Hudson Bay and James Bay, Quebec in the St. Lawrence Seaway as far as the city of Quebec, Newfoundland an ...
'' Fernald & Brackett – saltmarsh spikerush
*''
Eleocharis jacobsiana
''Eleocharis jacobsiana'' is a sedge of the family Cyperaceae that is native to Western Australia.
The species was first described in 2011 by Karen Wilson
Karen Louise Wilson (born 1950) is an Australian botanist.
Some of her research int ...
Eleocharis montevidensis
''Eleocharis montevidensis'' is a species of spikesedge known by the common name sand spikerush. It is a widespread coastal plant native to the Americas. It grows in moist, sandy spots in many habitat types, including lakes, riverbanks, wet mead ...
Eleocharis nitida
''Eleocharis nitida'' is a species of flowering plant commonly called neat spikerush, it is a member of the sedge family Cyperaceae.
Description
''Eleocharis nitida'' is a perennial growing from scaly, purplish rhizomes. The culms grow 1 to 8 i ...
Eleocharis pallens
''Eleocharis pallens'', commonly known as pale spikerush, is a sedge of the family Cyperaceae that is native to Australia.
The perennial herb to grass-like sedge typically grows to a height of and has a tufted habit. It blooms between July and ...
'' S.T.Blake – pale spikerush
*'' Eleocharis palustris'' (L.) Roem. & Schult. – common spikerush
*''
Eleocharis papillosa
''Eleocharis papillosa'' is a sedge of the family Cyperaceae that is native to Australia.
The annual herb produces brown flowers in November.
It has a scattered population that is found in and around open clay flats and clay pans in the Mid Wes ...
'' Latz
*'' Eleocharis parishii'' Britton – Parish's spikerush
*'' Eleocharis parvula'' (Roem. & Schult.) Link ex Bluff et al. – dwarf spikerush, hairgrass
*''
Eleocharis pellucida
''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' ...
Eleocharis quadrangulata
''Eleocharis quadrangulata'' is a species of spikesedge known by the common names square-stem spikerush and four-angled spikerush. It is native to eastern and central North America (from Texas and Florida north to Ontario and Massachusetts), wit ...
'' (Michx.) Roem. – squarestem spikerush
*''
Eleocharis quinqueflora
''Eleocharis quinqueflora'' is a species of spikesedge known by the common names fewflower spikerush and few-flowered spike-rush. It is widespread across Europe, North Africa, northern Asia (Siberia, China, Kazakhstan, Himalayas, etc.), and N ...
Eleocharis spiralis
''Eleocharis spiralis'' is a sedge of the family Cyperaceae that is native to Australia.
The rhizomatous perennial herb to grass-like sedge typically grows to a height of . It blooms between February and April producing white flowers.
It is fo ...
'' (Rottb.) Schult.
*''
Eleocharis sundaica
''Eleocharis sundaica'' is a sedge of the family Cyperaceae that is native to Australia.
The rhizomatous perennial herb to grass-like sedge typically grows to a height of and is sometime found partly submerged. It blooms between May and August ...