| Eleocharis | |
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| Eleocharis calva | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Poales |
| Family: | Cyperaceae |
| Genus: | Eleocharis R.Br.[1] |
| Synonyms[2] | |
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Eleocharis is a virtuallycosmopolitan genus of 250 or more species offlowering plants in the sedge family,Cyperaceae.[2] The name is derived from theGreek words ἕλειος (heleios), meaning "marsh dweller," and χάρις (charis), meaning "grace."[3] Members of the genus are known commonly asspikerushes orspikesedges. The genus has a geographicallycosmopolitan distribution, with centers of diversity in theAmazon Rainforest and adjacent eastern slopes of theSouth AmericanAndes, northernAustralia, easternNorth America,California,Southern Africa, and subtropicalAsia. The vast majority ofEleocharis species grow in aquatic or mesic habitats from sea level to higher than 5,000 meters in elevation (in the tropical Andes).[4]
The genus itself is relatively easy to recognize; allEleocharis 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 tropicalwetlands, while many others are smallcaespitose annual or perennial herbs growing near streams, and still others are intermediate. There are also a number of species that are obligateaquatic species, which usually have submerged, branching stems and often exhibit interesting photosynthetic adaptations, such as the ability to switch betweenC3 andC4 carbon fixation in response to different environmental stimuli. In allEleocharis species, the flowers are borne on unbranched terminal spikelets at the apices of stems.[5][6][7][8]
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 highlypolymorphic. 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.[citation needed]
One of the best known species is the Chinese water chestnut,Eleocharis dulcis. These plants bear tubers on their rhizomes which may be peeled and eaten raw or boiled. In Australia,magpie geese rely almost exclusively on these tubers for sustenance for a significant portion of the year.
Authority control databases: National |
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