Editing Gunnera (section)

==Description==
The 40–50 species vary enormously in [[leaf]] size, with the iconic large-leaved species belonging to the subgenus ''Panke''. 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 [[Wiktionary:reniform|reniform]] or sub-reniform leaves typically {{convert|1.5|to|2.0|m|ftin|sp=us}} long, not including the thick, succulent [[petiole (botany)|petiole]] which may be up to {{convert|2.5|m|ftin|abbr=off|sp=us}} in length. The width of the leaf blade is typically {{convert|2.5|m|ftin|abbr=off|sp=us}}, but on two occasions cultivated specimens (in [[Dorset]], England in 2011<ref>{{cite web|url=https://www.bbc.com/news/uk-england-berkshire-15308919|title=Abbotsbury Gardens celebrates plant's 'monster' leaves |date=14 October 2011 |website=[[BBC]]}}</ref> and at Narrowwater, [[Ulster]], [[Ireland]]<ref>{{cite journal | title = Unknown | journal = The Garden | location = London | volume = 63 | issue = 1631 | date = 21 February 1903 | page = 125 }}</ref> in 1903) produced leaves fully {{convert|3.3|m|ftin|abbr=off|sp=us}} in width. The seeds germinate best in very moist, but not wet, conditions and temperatures of 22–29&nbsp;°C.

Only slightly smaller is ''[[Gunnera masafuerae]]'' of the [[Juan Fernández Islands|Juan Fernandez Islands]] off the [[Chile]]an coast. They can have leaves up to {{convert|2.9|m|ftin|abbr=on}} in width on stout leaf stalks {{convert|1.5|m|ftin|abbr=on}} long and {{convert|11|cm|in|frac=2|abbr=on}} thick according to Skottsberg.<ref>{{cite book | vauthors = Skottsberg C | chapter = The Phanerogams of Juan Fernandez Islands | title = The Natural History of Juan Fernandez and Ester Islands | location = Uppsala | publisher = Almquist & Wiksells Boktryckeri AB | date = 1953 | volume = 2 | page = 151 }}</ref> These leaf stalks or [[Petiole (botany)|petiole]]s are the thickest of any [[dicot]], and probably also the most massive. On nearby [[Alejandro Selkirk Island|Isla Más Afuera]], ''[[Gunnera peltata]]'' frequently has an upright trunk to {{convert|5.5|m|ftin|abbr=on}} in height by {{convert|25|–|30|cm|in|frac=2|abbr=on}} thick, bearing leaves up to {{convert|2|m|ftin|abbr=on}} wide. The Hoja de Pantano (''[[Gunnera magnifica]]'') of the [[Colombia]]n [[Andes]] bears the largest leaf buds of any plant; up to {{convert|60|cm|ft|0|abbr=on}} long and {{convert|40|cm|in|0|abbr=on}} thick.<ref>{{cite journal | vauthors = St John H | title = ''Gunnera'' the Magnificent - Giant Herb of Colombia | journal = Chicago Natural History Museum Bulletin | volume = 30 | issue = 1 | date = January 1959 | page = 3 plus photo on front cover }}</ref> The [[Succulent plant|succulent]] leaf stalks are up to {{convert|2.7|m|ftin|abbr=on}} long. The massive [[inflorescence]] of small, reddish [[flower]]s is up to {{convert|2.3|m|ftin|abbr=on}} long and weighs about 13&nbsp;kg. The flowers of Gunnera species are dimerous ( two sepals, two petals (or none), two stamens (or one), and two carpels.<ref>{{cite web | url= https://www.plantsforuse.com/species/clusiaceae-garcinia#more-19 | work = Plants for Use  | title = Gunneraceae ''Gunnera'' | access-date= January 20, 2009 }}</ref> Other giant ''Gunnera'' species within the subgenus ''Panke'' are found throughout the [[Neotropics]] and [[Hawaii]]. ''Gunnera insignis'' is also known by the name "poor man's umbrella" in [[Costa Rica]].

Outside of the subgenus ''Panke'', most of the more basal ''Gunnera'' species have small-to-medium-sized leaves. There are some species with moderately large leaves in [[Africa]] (''G. perpensa'', in the subgenus ''Gunnera'' (which is redundant with ''Perpensum'')) and [[Southeast Asia]] (''G. macrophylla'', in the subgenus ''Pseudogunnera''), but the majority of more basal species are low-lying, mat-forming plants with small leaves. There are 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. The most basal species in the genus, ''G. herteri'' of Uruguay and Brazil, also has small leaves.<ref name=":1">{{Cite journal |last=WILKINSON |first=H |date=October 2000 |title=A revision of the anatomy of Gunneraceae |url=http://dx.doi.org/10.1006/bojl.2000.0372 |journal=Botanical Journal of the Linnean Society |volume=134 |issue=1–2 |pages=233–266 |doi=10.1006/bojl.2000.0372 |issn=0024-4074|url-access=subscription }}</ref><ref>{{Cite journal |last1=Rutishauser |first1=R. |last2=Wanntorp |first2=L. |last3=Pfeifer |first3=E. |date=2004 |title=''Gunnera herteri'' — developmental morphology of a dwarf from Uruguay and S Brazil (Gunneraceae) |url=https://www.jstor.org/stable/23654236 |journal=Plant Systematics and Evolution |volume=248 |issue=1/4 |pages=219–241 |doi=10.1007/s00606-004-0182-7 |jstor=23654236 |s2cid=24561923 |issn=0378-2697}}</ref>

Some fossil leaf impressions of ''Gunnera'' from the [[Cretaceous]] of [[North America]] have large leaves akin to those of ''Panke'', and the most basal extant species within ''Panke'' (''G. mexicana'') is the most northern member. For this reason, it has been suggested that ''Panke'' originates from South American ''Gunnera'' that colonized North America during the Cretaceous and grew into giant forms, with the remaining South American ''Gunnera'' evolving into the subgenus ''Misandra'', with a low-lying, matlike growth. During the Cenozoic, the North American ''Panke'' would have colonized [[Hawaii]] and retreated southwards on the mainland before recolonizing South America. However, more recent phylogenetic evidence suggests that ''Misandra'' and ''Panke'' diverged only 15 million years ago, much too recent to assign the Cretaceous ''Gunnera'' to ''Panke''. Due to this, the large-leaved Cretaceous ''Gunnera'' from North America may represent a distinct lineage that [[Convergent evolution|convergently evolved]] giant leaves similar to those of ''Panke'', but did not leave any descendants. ''<ref name=":0" />''<ref name=":1" /><ref>{{Cite journal |last1=Wanntorp |first1=Livia |last2=Wanntorp |first2=Hans-Erik |date=July 2003 |title=The biogeography of ''Gunnera'' L.: vicariance and dispersal: Biogeography of ''Gunnera'' |url=http://doi.wiley.com/10.1046/j.1365-2699.2003.00895.x |journal=Journal of Biogeography |language=en |volume=30 |issue=7 |pages=979–987 |doi=10.1046/j.1365-2699.2003.00895.x|s2cid=83697864 |url-access=subscription }}</ref>