Gunnera: Difference between revisions

Gunnera
	Gunnera tinctoria at the San Francisco Botanical Garden at Strybing Arboretum
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Core eudicots
Order:	Gunnerales
Family:	Gunneraceae
Genus:	Gunnera; L.
	The range of the genus Gunnera
Synonyms
	Milligania Hook.f., rejected name; Panke Molina; Pankea Oerst.;

Browse history interactively

← Previous edit Next edit →

Content deleted Content added

VisualWikitext

Inline

Revision as of 06:03, 8 August 2015

Gunnera is a genus of herbaceous flowering plants, some of them grow extremely large. The genus is the only member of the family Gunneraceae. It is native to Latin America, Australia, New Zealand, Papuasia, Hawaii, insular Southeast Asia, Africa, and Madagascar.^[2]

Description

The 40–50 species vary enormously in leaf size. The Giant Rhubarb, or Campos des Loges (Gunnera manicata), native to the Serra do Mar mountains of southeastern Brazil, is perhaps the largest species, with leaves typically 1.5 to 2.0 meters (5 to 6 feet) long (not including the thick, succulent leaf stalk (petiole) of up to 2.5 meters (8 feet)in length. The width is typically eight feet (2.5 meters), but on two separate occasions cultivated specimens (In Berkeshire, England quite recently ^[3] and at Narrowwater, Ulster,Ireland ^[4] in 1903) produced leaves fully eleven feet (3.4 meters) in width, making these leaves quite probably the largest of all dicot leaves. The seeds germinate best in very moist, but not wet, conditions and temperatures of 22–29 °C.

Only slightly smaller is G. masafuerae of the Juan Fernandez Islands off the Chilean 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. ^[5] On nearby Isla Más Afuera, G. peltata frequently has an upright trunk to 5.5 m (18 ft) in height by 25–30 cm (10–12 in) thick, bearing leaves up to 2 m (6 ft 4 inches) wide. The Hoja de Pantano (G. magnifica) of the Colombian Andes bears the largest leaf buds of any plant; up to 60 cm (2 ft) long and 40 cm (16 inches) thick. ^[6] The succulent leaf stalks are up to 2.7 m (8 ft 10 inches) long. The massive inflorescence of small, reddish flowers 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 1–2 cm long, and also in South America, with G. magellanica having leaves 5–9 cm wide on stalks 8–15 cm long.

This genus was named after the Norwegian botanist Johann Ernst Gunnerus.

Species^[2]

2

Cyanobacterial symbiosis

In nature, all Gunnera plants form a symbiosis with nitrogen-fixing cyanobacteria, thought to be exclusively Nostoc punctiforme. The bacteria enter the plant via glands found at the base of each leaf stalk^[1] 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 flowering 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), from Southern Chile and Argentina, 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.^{[citation needed]}

References

^ ^a ^b Bergman, B.; Johansson, C.; Söderbäck, E. (1992). "The Nostoc–Gunnera symbiosis". New Phytologist. 122 (3): 379. doi:10.1111/j.1469-8137.1992.tb00067.x.
^ ^a ^b ^c Kew World Checklist of Selected Plant Families
^ www.bbc.co.uk/news/uk-england-berkeshire-15308919
^ The Garden (London) Vol. 63 # 1631 (February 21, 1903) p. 125.
^ Dr Carl Skottsberg, , "The Phanerogams of Juan Fernandez Islands", NATURAL HISTORY OF JUAN FERNANDEZ AND EASTER ISLAND (Uppsala: Almqvist & Wiksells Buktrykeri A.S., 1953) Vol. 2 p.151.
^ Dr. Harold St. John, "Gunnera the Magnificent - Giant Herb of Colombia", CHICAGO NATURAL HISTORY MUSEUM BULLETIN, Vol. 30 # 1 (January 1959) p. 3 plus photo on front cover.

External links

The Gunnera Gallery
Gunnera magellanica pictures from Chilebosque
Global Invasive Species database Gunnera tinctoria
Medicinal plant details Gunnera perpensa
Gunnera on Achill Island [1]

[Bergman-1] Bergman, B.; Johansson, C.; Söderbäck, E. (1992). "The Nostoc–Gunnera symbiosis". New Phytologist. 122 (3): 379. doi:10.1111/j.1469-8137.1992.tb00067.x.

[l-2] Kew World Checklist of Selected Plant Families

[3] www.bbc.co.uk/news/uk-england-berkeshire-15308919

[4] The Garden (London) Vol. 63 # 1631 (February 21, 1903) p. 125.

[5] Dr Carl Skottsberg, , "The Phanerogams of Juan Fernandez Islands", NATURAL HISTORY OF JUAN FERNANDEZ AND EASTER ISLAND (Uppsala: Almqvist & Wiksells Buktrykeri A.S., 1953) Vol. 2 p.151.

[6] Dr. Harold St. John, "Gunnera the Magnificent - Giant Herb of Colombia", CHICAGO NATURAL HISTORY MUSEUM BULLETIN, Vol. 30 # 1 (January 1959) p. 3 plus photo on front cover.

[1]

[2]

[3]

[4]

[5]

[6]

@@ Line 23: / Line 23: @@
 ==Description==
-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&nbsp;ft) wide, but exceptionally long, up to 3.4&nbsp;m (11&nbsp;ft), borne on thick, succulent leaf stalks ([[Petiole (botany)|petioles]]) up to 2.5&nbsp;m (8&nbsp;ft) long. It germinates best in very moist, but not wet, conditions and temperatures of 22–29 °C.
+The 40–50 species vary enormously in [[leaf]] size. The Giant Rhubarb, or Campos des Loges (''[[Gunnera manicata]]''), native to the Serra do Mar mountains of southeastern [[Brazil]], is perhaps the largest species, with leaves typically 1.5 to 2.0&nbsp;meters (5 to 6&nbsp;feet) long (not including the thick, succulent leaf stalk ([[petiole]]) of up to 2.5&nbsp;meters (8&nbsp;feet)in length.  The width is typically eight feet (2.5&nbsp;meters),  but on two separate occasions cultivated specimens (In Berkeshire, England quite recently  <ref> www.bbc.co.uk/news/uk-england-berkeshire-15308919 </ref> and at Narrowwater, [[Ulster]],[[Ireland]] <ref> The Garden (London) Vol. 63 # 1631 (February 21, 1903) p. 125. </ref> in 1903) produced leaves fully eleven feet (3.4&nbsp;meters) in width, making these leaves quite probably the largest of all [[dicot]] leaves. The seeds germinate best in very moist, but not wet, conditions and temperatures of 22–29 °C.
-Only slightly smaller is ''G. masafuerae'' of the [[Juan Fernández Islands|Juan Fernandez Islands]] off the [[Chile]]an coast. They can have leaves up to 2.9 m (9&nbsp;ft 5 inches) in width on stout leaf stalks 1.5&nbsp;m (5&nbsp;ft) long and 11&nbsp;cm (4.5&nbsp;in) thick according to Skottsberg. On nearby [[Alejandro Selkirk Island|Isla Más Afuera]], ''G. peltata'' frequently has an upright trunk to 5.5&nbsp;m (18&nbsp;ft) in height by 25–30&nbsp;cm (10–12 in) thick, bearing leaves up to 2 m (6&nbsp;ft 4 inches) wide. ''G. magnifica'' of the [[Colombia]]n [[Andes]] bears the largest leaf buds of any plant; up to 60&nbsp;cm (2&nbsp;ft) long and 40&nbsp;cm (16 inches) thick. The [[Succulent plant|succulent]] leaf stalks are up to 2.7 m (8&nbsp;ft 10 inches) long. The massive [[inflorescence]] of small, reddish [[flower]]s is up to 2.3 m (7&nbsp;ft 6 inches) long and weighs about 13&nbsp;kg. Other giant ''Gunnera'' species are found throughout the [[Neotropics]] and [[Hawaii]].
+Only slightly smaller is ''G. masafuerae'' of the [[Juan Fernández Islands|Juan Fernandez Islands]] off the [[Chile]]an coast. They can have leaves up to 2.9 m (9&nbsp;ft 5 inches) in width on stout leaf stalks 1.5&nbsp;m (5&nbsp;ft) long and 11&nbsp;cm (4.5&nbsp;in) thick according to Skottsberg. <ref> Dr Carl Skottsberg, , "The Phanerogams of Juan Fernandez Islands", NATURAL HISTORY OF JUAN FERNANDEZ AND EASTER ISLAND (Uppsala: Almqvist & Wiksells Buktrykeri A.S., 1953) Vol. 2 p.151. </ref> On nearby [[Alejandro Selkirk Island|Isla Más Afuera]], ''G. peltata'' frequently has an upright trunk to 5.5&nbsp;m (18&nbsp;ft) in height by 25–30&nbsp;cm (10–12 in) thick, bearing leaves up to 2 m (6&nbsp;ft 4 inches) wide. The Hoja de Pantano (''G. magnifica'') of the [[Colombia]]n [[Andes]] bears the largest leaf buds of any plant; up to 60&nbsp;cm (2&nbsp;ft) long and 40&nbsp;cm (16 inches) thick. <ref> Dr. Harold St. John, "Gunnera the Magnificent - Giant Herb of Colombia", CHICAGO NATURAL HISTORY MUSEUM BULLETIN, Vol. 30 # 1 (January 1959) p. 3 plus photo on front cover. </ref> The [[Succulent plant|succulent]] leaf stalks are up to 2.7 m (8&nbsp;ft 10 inches) long. The massive [[inflorescence]] of small, reddish [[flower]]s is up to 2.3 m (7&nbsp;ft 6 inches) long and weighs about 13&nbsp;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 1–2&nbsp;cm long, and also in South America, with ''G. magellanica'' having leaves 5–9&nbsp;cm wide on stalks 8–15&nbsp;cm long.