''Centella cordifolia'', commonly known as swamp pennywort or arthritis herb, is a trailing

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 ...

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

native to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. The species is common in preferred local environments. It potentially has medicinal purposes and indigenous cultural significance. ''C. cordifolia'' can be sourced commercially at Australian plant nurseries.

Description

''Centella cordifolia'' is a groundcover herb that can grow up to tall, and typically stretches wide. Leaves are heart-shaped (

cordate Cordate is an adjective meaning ' heart-shaped' and is most typically used for: * Cordate (leaf shape), in plants * Cordate axe, a prehistoric stone tool See also * Chordate A chordate ( ) is a bilaterian animal belonging to the phyl ...

), glabrescent, glossy and dark green. The lamina is in length (with a similarly sized width), with five to seven veins and scarious margins. When exposed directly to the sun, the leaves sit lowered, towards the ground, whereas in the shade they will stand upright. The petiole has a purple tint, sheathing and broad at the base, and can be up to five times the length of the lamina. Flowers occur in subsessile

umbel UMBEL (Upper Mapping and Binding Exchange Layer) is a logically organized knowledge graph of 34,000 concepts and entity types that can be used in information science for relating information from disparate sources to one another. It was retired ...

s in an ovate shape, in length and each containing two to three florets. Petals are purple or white, ovate, and approximately in length. Sepals form a very small, lobed ring, and at the base are two involucral bracts. Anthers are dark purple. Flowering times for ''C. cordifolia'' occur between late summer (December) to early autumn (March). Fruit is small, rounded, laterally compressed and contains seeds. five longitudinal ribs span the mericarp, which is in length and in width. Small hairs towards the apex can be present, but in general the fruit is glabrous. Distinguishing ''C. cordifolia'' from other ''

Centella ''Centella'' is a genus of 53 species of flowering plants in the subfamily Mackinlayoideae. The genus is sometimes placed in family Araliaceae; however, recent studies utilising molecular data place ''Centella'' within Apiaceae Apiaceae ( ...

'' species can be difficult, particularly from '' C. asiatica'', which also inhabits parts of Australia. The leaf margins of ''C. cordifolia'' are more serrate, whereas '' C. asiatica'' have more dentate margins. ''C. cordifolia'' also has mat-like growth habit, which can be distinguished from other ''

'' species that have greater vertical and spreading growth habits.

Distribution and habitat

''Centella cordifolia'' is native to

, growing in parts of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

and

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. However, the species has limited records and distribution lacks an extensive understanding. The herb grows in damp, poorly drained environments, including marshy soils or shallow waters. Sun exposure can range from full to partial shade. It is intolerant to phosphorus and moderately frost tolerant.

Ecological processes

''Centella cordifolia'' forms part of the understory in the various damp environments it inhabits. It can provide a habitat for frogs. Its root system stabilizes the damp soils it can grow in, preventing erosion.

Medicinal and cultural significance

''Centella cordifolia'' is known to treat rheumatism and arthritis, though widespread adoption and evidence for this is limited. The herb is said to have an indigenous cultural significance, again with limited information available. ''C. cordifolia'' is closely related to ''

Centella asiatica ''Centella asiatica'', commonly known as Indian pennywort, Asiatic pennywort, spadeleaf, coinwort or gotu kola, is a herbaceous, perennial plant in the flowering plant family Apiaceae. It is native to tropical regions of Africa, Asia, Australia, ...

'' and their uses may be interchangeable. ''C. asiatica'' is widespread across

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, with well-known cultural, medicinal and culinary uses. In a 2017 study published by ''

Frontiers in Plant Science ''Frontiers in Plant Science'' is a peer-reviewed scientific journal covering all aspects of botany. It was established in 2010 and is published by Frontiers Media. The editor-in-chief is Yunde Zhao (University of California, San Diego). Abstract ...

''. ''C. cordifolia'' was found to be genetically and chemically similar to '' C. asiatica'', when comparing three ''

'' species (''C. cordifolia'', '' C. asiatica'' and '' C. erecta'').

References

{{Taxonbar, from1=Q15568395 Mackinlayoideae Flora of Australia Plants described in 1840 Taxa named by Joseph Dalton Hooker