''Gunnera manicata'', known as Brazilian giant-rhubarb or giant rhubarb, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Gunneraceae from the coastal Serra do Mar Mountains of Santa Catarina, Parana and Rio Grande do Sul States, Brazil. In cultivation, the name ''G. manicata'' has regularly been wrongly applied to the hybrid with '' G. tinctoria'', ''G.'' × ''cryptica''.

Description

''Gunnera manicata'' is a large, clump-forming

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

growing to tall by or more in width. The leaves of ''G. manicata'' grow to an impressive size. Leaves with diameters well in excess of are commonplace, with a spread of on a mature plant. The largest on record had leaves up to in width. It is the largest of all the ''Gunnera'' species, but not the tallest (see '' Gunnera masafuerae''). The underside of the leaf and the whole stalk have spikes on them. In early summer it bears tiny red-green, dimerous flowers in conical branched panicles, followed by small, spherical fruit. Like most gunneras, it has a symbiotic relationship with certain

blue-green algae Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteria' ...

which provide nitrogen by fixation. Despite the common name "giant rhubarb" it is not closely related to true

rhubarb Rhubarb is the fleshy, edible stalks ( petioles) of species and hybrids (culinary rhubarb) of ''Rheum'' in the family Polygonaceae, which are cooked and used for food. The plant is a herbaceous perennial that grows from short, thick rhizomes. ...

. It was named after the Norwegian bishop and naturalist Johan Ernst Gunnerus, who also named and published a description about the

basking shark The basking shark (''Cetorhinus maximus'') is the second-largest living shark and fish, after the whale shark. It is one of three Planktivore, plankton-eating shark species, along with the whale shark and megamouth shark. Typically, basking sh ...

Distribution

''Gunnera manicata'' is native to the

Serra do Mar The Serra do Mar (; ) is a system of mountain ranges and escarpments in Southeast Region, Brazil, Southeastern Brazil. Geography The Serra do Mar runs parallel to the Atlantic Ocean coast from the state of Espírito Santo to southern Santa Ca ...

mountains of coastal Santa Catarina and Rio Grande do Sul states, Brazil, where it is used in traditional medicine for

sexually transmitted diseases A sexually transmitted infection (STI), also referred to as a sexually transmitted disease (STD) and the older term venereal disease (VD), is an infection that is spread by sexual activity, especially vaginal intercourse, anal sex, oral ...

. File:Gunnera manicata 'Aparados da serra' BBM20.BR2261, jardin jungle karlostachys.jpg, ''Gunnera manicata'' in the jungle garden in France File:Gunnera au Jardin Jungle Karlostachys.jpg, ''Gunnera'' × ''cryptica'', jardin jungle

Cultivation

Giant rhubarb came to be widely cultivated in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

and

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

as an ornamental garden plant. It was primarily grown for its massive leaves. It grows best in damp conditions such as near garden ponds, but dislikes winter cold and wet. However, in 2022, the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

found that these plants were actually ''Gunnera'' × ''cryptica'', a hybrid of ''G. manicata'' with highly invasive '' Gunnera tinctoria''. In December 2023, the UK

Department for Environment, Food and Rural Affairs The Department for Environment, Food and Rural Affairs (Defra) is a Departments of the Government of the United Kingdom, ministerial department of the government of the United Kingdom. It is responsible for environmental quality, environmenta ...

banned ''Gunnera'' × ''cryptica'': it cannot be sold or cultivated, and those who have it in their gardens must ensure it does not spread.

References

External links

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''Gunnera manicata''
{{Taxonbar, from=Q1634712 manicata Flora of Brazil Plants described in 1867