Posidonia australis
Posidonia australis | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Alismatales |
Family: | Posidoniaceae |
Genus: | Posidonia |
Species: | P. australis
|
Binomial name | |
Posidonia australis Hook.f. |
Posidonia australis, also known as fibre-ball weed or ribbon weed, is a species of seagrass that occurs in the southern waters of Australia. It forms large meadows important to environmental conservation. Balls of decomposing detritus from the foliage are found along nearby shore-lines.
In 2022, a single stand in Shark Bay was reported by scientists to not only be the largest plant in the world, but the largest organism by square size.[2]
Description
Posidonia australis is a flowering plant occurring in dense meadows, or along channels, in white sand. It is found at depths from 1–15 m (3–49 ft). Subsurface rhizomes and roots provide stability in the sands it occupies. Erect rhizomes and leaves reduce the accumulation of silt.
The leaves are ribbon-like and 11–20 mm (0.43–0.79 in) wide. They are bright green, perhaps becoming browned with age.[3] The terminus of the leaf is rounded or absent through damage. They are arranged in groups with older leaves on the outside, longer and differing in form from the younger leaves they surround.
The species is
Posidonia australis reproduction usually occurs through sexual or asexual methods but, under extreme conditions, by
A 2013 study showed that P. australis can sequester carbon 35 times more efficiently than rainforests.[6]
In 2022, a study by the School of Biological Sciences and Oceans Institute at The University of Western Australia showed that a single plant of this species can grow vegetatively by using rhizomes to cover an extensive area, similar to buffalo grass. This particular specimen has double the number of chromosomes of other studied populations (40 chromosomes instead of the usual 20).[7]
Distribution
This species is found in waters around the southern coast of Australia. In
A sign of a nearby occurrence of Posidonia is the presence of masses of decomposing leaves on beaches, forming fibrous balls.
Largest known organism
A research article in the Proceedings of the Royal Society
The plant is estimated to have taken at least 4,500 years[8] to grow to this size by using rhizomes to colonise new parts of the seafloor, assuming a rhizome growth rate of around 35 cm (14 in) a year.[10][9] This age puts it among the oldest known clonal plants too.
Taxonomy
This species is a member of the family
The species was first described by Joseph Hooker in Flora Tasmaniae.[11] Common names for the plant include fibre-ball weed and ribbon weed.[9]
Conservation status
IUCN lists this species as "near threatened",
References
- ^ . Retrieved 19 November 2021.
- ^ "It's a clone, and it's massive: World's largest plant found off WA coast". Australia: ABC News. 31 May 2022. Retrieved 11 October 2023.
- Department of Biodiversity, Conservation and Attractions.
- ^ a b Mike van Keulen. "The genus Posidonia König (nom. cons.) (Posidoniaceae)". Murdoch University.
- ^ Elizabeth Sinclair. What happens when (plant) sex fails? Atlas of Science, 2016
- ^ "Humble plants may save the planet". University of Technology, Sydney. 14 August 2013. Archived from the original on 19 August 2013. Retrieved 15 August 2013.
- ^ Katie Hunt. "World's largest plant discovered in Australia". CNN. Retrieved 2 June 2022.
- ^ PMID 35642363. Retrieved 1 June 2022.
- ^ a b c d Readfearn, Graham (1 June 2022). "Scientists discover 'biggest plant on Earth' off Western Australian coast". The Guardian. Retrieved 1 June 2022.
- ^ Kilvert, Nick (1 June 2022). "World's largest plant discovered right under our noses in Western Australia". Australia: ABC News. Retrieved 1 June 2022.
- ^ Hooker, J. D. (1860). The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror. Vol. III Flora Tasmaniæ II Monocotyledones and Acotyledones. p. 43.
- ^ Australian Government. "Species Profile and Threats Database: Posidonia australis seagrass meadows of the Manning-Hawkesbury ecoregion". Department of Agriculture, Water and the Environment.
External links
- Posidonia australis occurrence data from Australasian Virtual Herbarium
- "Posidonia australis". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government.
- Tyerman, SD; Hatcher, AI; West, RJ; Larkum, AWD (1984). "Posidonia australis Growing in Altered Salinities: Leaf Growth, Regulation of Turgor and the Development of Osmotic Gradients". Functional Plant Biology. 11 (2). .