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

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Gunneraceae from the coastal Serra do Mar Mountains of Santa Catarina, Parana and Rio Grande do Sul States, Brazil. gunnera

It 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 ...

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

growing to tall by or more. 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 eleven feet (3.3 meters) in width. The underside of the leaf and the whole stalk have spikes on them. In early summer it bears tiny red-green,

dimerous Merosity (from the greek "méros," which means "having parts") refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a w ...

flowers in conical branched panicles, followed by small, spherical fruit. However, it is primarily cultivated for its massive leaves. Like most Gunneras, it has a symbiotic relationship with certain

blue-green algae Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue ...

which provide nitrogen by fixation. This plant grows best in damp conditions such as near garden ponds, but dislikes winter cold and wet. Despite the common name "giant rhubarb", this plant 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 whole plant – a herbaceous perennial growing from short, thick r ...

. It was named after a 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, and one of three plankton-eating shark species, along with the whale shark and megamouth shark. Adults typically reach in leng ...

. It is native to the

Serra do Mar The Serra do Mar (, Portuguese for ''Sea's Ridge'' or ''Sea Ridge'') is a 1,500 km long system of mountain ranges and escarpments in Southeastern Brazil. Geography The Serra do Mar runs parallel to the Atlantic Ocean coast from the state ...

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

sexually transmitted diseases Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are Transmission (medicine), spread by Human sexual activity, sexual activity, especi ...

References

External links

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