Editing Cladium (section)

{{Short description|Genus of grass-like plants}}
{{Use dmy dates|date=August 2022}}
{{Automatic taxobox
|image = Cladium mariscus.jpeg
|image_caption = ''[[Cladium mariscus]]''
|taxon = Cladium
|authority = [[Patrick Browne (physician)|P.Browne]]
|synonyms_ref = <ref name=jodi/>
|synonyms = *''Mariscus'' <small>Scop.</small>
*''Trasis'' <small>P.Beauv. in T.G.Lestiboudois</small>
}}

'''''Cladium''''' ('''fen-sedge''', '''sawgrass''' or '''twig-sedge''') is a genus of large [[Cyperaceae|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 (sawtooth-like) margins, and [[flower]]ing stems 1–3 m tall bearing a much-branched [[inflorescence]]. Like many plants found in wet habitats, it has deeply buried rhizomes that can produce tall shoots with dense canopies.<ref>Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. p. 89</ref>

''Cladium mariscus ''subsp.'' jamaicense'', or saw-grass, is common in marshes and savannas throughout the tropical [[Americas]].  One typical and well-known area of extensive saw-grass growth is the [[Florida]] [[Everglades]];<ref>Loveless, C. M. 1959. "A study of the vegetation in the Florida Everglades". ''Ecology'' 40: 1–9.</ref> sawgrass is the plant referred to by the descriptor, "[[The Everglades: River of Grass|River of Grass]]". Like many species of the Everglades, ''C. jamaicense'' grows in extremely infertile conditions, particularly wet sites that are low in [[phosphorus]].<ref>Davis, S. M. and Ogden, J. C. (eds.) 1994. ''Everglades: The Ecosystem and its Restoration''. Delray Beach, FL: St. Lucie Press.</ref> Dense sawgrass beds are intermingled with other vegetation types. Together they produce a rich array of habitats that support the biological diversity of the Everglades.<ref>White, P. S. (1994). "Synthesis: vegetation pattern and process in the Everglades ecosystem". In ''Everglades: The Ecosystem and Its Restoration'', eds. S. Davis and J. Ogden, pp. 445–60. DelRay Beach, FL: St. Lucie Press.</ref> [[American alligator]]s also use sawgrass to build nests.<ref>Lodge, Thomas E. (1994). ''The Everglades Handbook: Understanding the Ecosystem''. St. Lucie Press, DelRay Beach, Fl.</ref> Phosphorus from [[agricultural pollution|agricultural runoff]] favoured dense [[cattail]] over rich sawgrass habitats, choking off water access for animals and birds. Eighty plant and animal species in the Everglades are threatened or endangered.<ref>Richard Blaustein: "Climate change prompts a rethink of Everglades management". ''Science News'', October 18, 2018. {{doi|10.1126/science.aav7879}}.</ref>

''Cladium mariscoides'', or twig-rush, is also a wetland plant, but is found further north, and in other kinds of wetlands including [[fen]]s,<ref>Godwin, K. S., Shallenberger, J., Leopold, D. J., and Bedford, B. L. (2002). "Linking landscape properties to local hydrogeologic gradients and plant species occurrence in New York fens: a hydrogeologic setting (HGS) framework". ''Wetlands'', 22, 722–37. Table 3.</ref> [[wet meadow]]s<ref>Wisheu, I. C. and Keddy, P. A. 1989. "The conservation and management of a threatened coastal plain plant community in eastern North America (Nova Scotia, Canada)". ''Biological Conservation'', 48, 229–38.</ref> and pond shores.<ref>{{cite web |title=Twig-rush sandy turf pond shore (S1) |url=http://www.nhdfl.org/about-forests-and-lands/bureaus/natural-heritage-bureau/photo-index/twig-rush-sandy-turf-pond-shore.aspx |archive-url=https://web.archive.org/web/20100717020732/http://www.nhdfl.org/about-forests-and-lands/bureaus/natural-heritage-bureau/photo-index/twig-rush-sandy-turf-pond-shore.aspx |archive-date=17 July 2010}}</ref> Owing to such specific habitat requirements, it is quite rare in the northern states such as Minnesota.<ref name="dnr.state.mn.us">{{Cite web|url=http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=PMCYP04050|title = Cladium mariscoides : Twig Rush &#124; Rare Species Guide}}</ref> "Finding a self-sustaining population of ''C. mariscoides'' on a lake shore is indeed a very rare event in Minnesota".<ref name="dnr.state.mn.us"/>

''Cladium mariscus'' is frequently encountered in English fens.<ref>Wheeler, B. D. and Proctor, M. C. F. 2000. "Ecological gradients, subdivisions and terminology of north-west European mires". ''Journal of Ecology'', 88, 187–203.</ref> Its ability to form dense stands can lead to reduced plant diversity.<ref>Wheeler, B. D. and K. E. Giller. 1982. "Species richness of herbaceous fen vegetation in Broadland, Norfolk in relation to the quantity of aboveground plant material". ''Journal of Ecology'' 70: 179–200.</ref> Hence, it is sometimes mowed to reduce dominance.<ref>Elveland, J. and Sjoberg, K. 1982. Some Effects of Scything and Other Management Procedures on the Plant and Animal Life of N. Swedish Wetlands Formerly Mown for Hay, Statens naturvardsverket PM 1516. Solna, Sweden: Forskningssekretariatet.</ref>

Sawgrass may be useful as a source for developing [[biofuel]] ([[ethanol fuel|ethanol]]), possibly replacing [[Maize|corn]] as the [[cellulose]] (the basis for developing ethanol) source of choice.<ref>{{cite journal |last=Service |first=Robert F. |date=January 7, 2008 |title=Biofuels on a Big Scale |url=http://sciencenow.sciencemag.org/cgi/content/full/2008/107/1 |journal=[[ScienceNOW]] |access-date=14 November 2019 |archive-date=7 August 2008 |archive-url=https://web.archive.org/web/20080807130112/http://sciencenow.sciencemag.org/cgi/content/full/2008/107/1 |url-status=dead }}</ref> On Gotland, a limestone island in the Baltic sea, Cladium mariscus is used for thatching.