Wednesday 1 June 2022 10:19 AM World's largest plant is an Australian seagrass meadow that stretches more than ... trends now
Stand down, beanstalks and giant vegetables - the world's largest plant has been discovered.
An Australian seagrass meadow has been announced as the biggest plant in the world, and is at least as old as Egypt's great pyramids.
The aquatic ribbon weed covers about 77 square miles (200 square kilometres) of Shark Bay in Western Australia and has been hiding in plain site.
It was long believed to be a collection of genetically varied individuals, but tests have revealed that, genetically speaking, it is all one entity.
The humongous plant, Posidonia australis, began life about 4,500 years ago when the ancient Egyptians were building the pyramids at Giza.
There are older seagrasses and terrestrial plants elsewhere in the world, but none are believed to be as large as this.
The record-breaking aquatic ribbon weed covers about 77 square miles (200 square kilometres) of Shark Bay in Western Australia
Map of Shark Bay, Gathaagudu, Western Australia showing distribution of dense and sparse persistent seagrass cover in 2016 and study sample points (1 - Sandy Point, Dirk Hartog Island; 2 - Middle Bluff; 3 - Fowlers Camp; 4 - Nanga Bay; 5 - White Island; 6 - Herald Bight; 7 - Guischenault Point; 8 - Monkey Mia; 9 - Dubaut Point; 10 - Faure Sill)
Seagrasses are marine plants that produce roots and flowers like land plants
They grow in shallow coastal waters with lots of light and sandy or muddy bottoms
Shark Bay is buffered from ocean swells that could break the plant apart, and help it tolerate a wide range of temperatures and salinities
The meadows also grow in lines parallel to prevailing currents
These growing conditions result in the seagrass producing about eight million tonnes of leaf material each year
Twelve of the world’s 60 species of seagrass are found in Shark Bay, with wireweed and ribbonweed being the two most common
The seagrass banks at the bay are the biggest in the world
Many species depend on seagrass, including a large dugong population that moves between different meadows during the year
Source: Sharkbay.org
Seagrass supports marine life like dugongs, turtles and dolphins as well as thousands of fish species (stock image)
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Flinders University ecologist Dr Martin Breed co-authored a recently published study on the ribbon weed that explains its extraordinary longevity.
'It's like someone's lawn. It grows through rhizomes, these underground suckers, and then it pops up and green shoots appear,' he said.
'What we've observed in Shark Bay is essentially an extremely large lawn that has expanded and grown across a very large area.
'There are some parts of the lawn that have died but there's lots of parts that are still alive.'
The study's senior author, University of Western Australia (UWA) evolutionary biologist Dr Elizabeth Sinclair, said the ribbon weed is a polyploid, meaning it has twice as many chromosomes as its oceanic relatives.
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