Gunnera 404942 222330886 2008-06-28T19:36:10Z DOI bot 6652755 Citation maintenance. Added: title, year, author, journal, volume, pages. Initiated by [[User:Kingdon|Kingdon]]. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{Taxobox | name = ''Gunnera'' | image = Gunnera tinctoria 2.jpg | image_width = 240px | image_caption = ''Gunnera tinctoria'' at the [[San Francisco Botanical Garden]] at Strybing Arboretum | regnum = [[Plant]]ae | divisio = [[Magnoliophyta]] | classis = [[Magnoliopsida]] | ordo = [[Gunnerales]] | familia = '''[[Gunneraceae]]''' | familia_authority = [[Meisner]] | genus = '''''Gunnera''''' | genus_authority = [[Carolus Linnaeus|L.]] | subdivision_ranks = [[Species]] | subdivision = See text. }} '''''Gunnera''''' is a genus of [[herbaceous]] [[flowering plant]]s, some of them gigantic. The genus is the only member of the family Gunneraceae. The 40-50 species vary enormously in [[leaf]] size. ''[[Gunnera manicata]]'', native to the Serra do Mar mountains of southeastern [[Brazil]], is perhaps the largest species, with leaves typically 1.5-2 m (5-6 ft) wide, but exceptionally long, up to 3.4 m (11 ft), borne on thick, succulent leaf stalks ([[Petiole (botany)|petioles]]) up to 2.5 m (8 ft) long. It germinates best in very moist, but not wet, conditions and temperatures of 22 to 29 °C. Only slightly smaller is ''G. masafuerae'' of the [[Juan Fernández|Juan Fernandez Islands]] off the [[Chile]]an coast. They can have leaves up to 2.9 m (9 ft 5 inches) in width on stout leaf stalks 1.5 m (5 ft) long and 11 cm (4.5 in) thick according to Skottsberg. On nearby [[Alejandro_Selkirk_Island|Isla Más Afuera]], ''G. peltata'' frequently has an upright trunk to 5.5 m (18 ft) in height by 25&ndash;30 cm (10&ndash;12 in) thick, bearing leaves up to 2 m (6 ft 4 inches) wide. ''G. magnifica'' of the [[Colombia]]n [[Andes]] bears the largest leaf buds of any plant; up to 60 cm (2 ft) long and 40 cm (16 inches) thick. The [[Succulent plant|succulent]] leaf stalks are up to 2.7 m (8 ft 10 inches) long. The massive [[inflorescence]] of small, reddish [[flower]]s is up to 2.3 m (7 ft 6 inches) long and weighs about 13 kg. Other giant ''Gunnera'' species are found throughout the [[Neotropics]] and [[Hawaii]]. Several small species are found in [[New Zealand]], notably ''G. albocarpa'', with leaves only 1&ndash;2 cm long, and also in South America, with ''G. magellanica'' having leaves 5&ndash;9 cm wide on stalks 8&ndash;15 cm long. Commonly known as "giant [[rhubarb]]". [[Image:gunnera.manicata.arp.750pix.jpg|thumb|right|200px|''Gunnera manicata'' Devon, England]] This genus was named after the Norwegian botanist [[Johann Ernst Gunnerus]]. ;Selected species *''[[Gunnera albocarpa]]'' *''[[Gunnera arenaria]]'' *''[[Gunnera densiflora]]'' *''[[Gunnera dentata]]'' *''[[Gunnera flavida]]'' *''[[Gunnera hamiltonii]]'' *''[[Gunnera kauaiensis]]'' *''[[Gunnera magellanica]]'' *''[[Gunnera magnifica]]'' *''[[Gunnera manicata]]'' *''[[Gunnera masafuerae]]'' *''[[Gunnera monoica]]'' *''[[Gunnera perpensa]]'' *''[[Gunnera petaloïdea]]'' *''[[Gunnera prorepens]]'' *''[[Gunnera tinctoria]]'' ===Cyanobacterial Symbiosis=== In nature, all Gunnera plants form a symbiosis with a nitrogen-fixing cyanobacteria, thought to be exclusively ''[[Nostoc punctiforme]]''. The bacteria invade the plant via glands found at the base of each leaf stalk<ref>{{cite journal | doi = 10.1111/j.1469-8137.1992.tb00067.x | title = The Nostoc-Gunnera symbiosis | year = 1992 | author = Bergman, B. | journal = New Phytologist | volume = 122 | pages = 379 }} <!-- http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1469-8137.1992.tb00067.x --> </ref> and initiate an intracellular symbiosis which is thought to provide the plant with fixed nitrogen in return for fixed carbon for the bacterium. This intracellular interaction is unique in higher plants and may provide insights to allow the creation of novel symbioses between crop plants and cyanobacteria, allowing growth in areas lacking fixed nitrogen in the soil. ===Uses=== The stalks of ''G. tinctoria'' (''nalcas'') are edible. Their principal use is fresh consumption, but also they are prepared in salads, liquor or marmalade. Leaves of this species are used in covering [[curanto]] (a traditional Chilean food). ''Gunnera perpensa'' is used as a source of traditional medicine in Southern Africa. ==References== {{reflist}} ==External links== * [http://gunneraceae.googlepages.com/home The Gunnera Gallery] * [http://www.chilebosque.cl/herb/gmage.html ''Gunnera magellanica'' pictures from ''Chilebosque''] * Global Invasive Species database [http://www.issg.org/database/species/ecology.asp?si=836&fr=1&sts= Gunnera tinctoria] * Medicinal plant details [http://www.plantzafrica.com/medmonographs/gunnerapers.pdf Gunnera perpensa] * Gunnera on Achill Island [http://www.achilljournal.com/index.php/2007/03/20/e15000-for-achills-wild-rhubarb/] * Fullscreen QTVR panorama [http://www.lookaroundcornwall.com/panos/trebah_gunnera.htm Gunnera Manicata at Trebah Garden Cornwall] [[Category:Gunnerales]] [[Category:Invasive plant species]] [[Category:Plants named after people]] [[da:Gunnera]] [[de:Gunnera]] [[es:Gunnera]] [[fr:Gunnera]] [[nl:Mammoetblad]]