World’s largest plant discovered off the coast of Australia

World’s largest plant discovered off the coast of Australia

By Liam Taylor  July 13th, 2022

A single seagrass seed that happened to take root off the coast of Western Australia over 4,500 years ago has grown into a simply massive seagrass – taking the crown of the world’s largest plant.


Spanning about 200 square kilometres (the size of roughly 28,000 soccer fields), the seagrass meadow is about triple the size of the island of Manhattan. The discovery of the single plant, which has cloned itself over four millennia, was recently detailed in a new study published in Proceedings of the Royal Society B.

The discovery occurred by accident, with researchers initially wanting to study how genetically diverse the seagrass meadows in the Shark Bay area were to learn which plants should be collected for seagrass restoration projects. In order to determine this, they took samples from across the meadow in various environments that were intended to provide a snapshot of the genes in the area.

“The answer blew us away – there was just one!” said University of Western Australia (UWA) student researcher Jane Edgeloe in a press release.

“That’s it, just one plant has expanded over 180km in Shark Bay, making it the largest known plant on earth.The existing 200km2 of ribbon weed meadows appear to have expanded from a single, colonising seedling.”

The plant has been extremely successful despite testing conditions such as temperature disparity, a wide range of salinities and extreme light. The research, made possible through a collaboration between UWA, Flinders University and Kings Park Science, will now proceed with additional experiments in Shark Bay to understand how the single plant has managed to continually survive and clone itself over time despite these variable conditions.

The results of this follow-up research could provide learnings that will help restore seagrass meadows that have experienced decline over recent decades in areas around Australia. Australia has the highest diversity of seagrasses in the world and seagrass meadows are an extremely important habitat and food source for marine species including marine turtles, dugongs, octopuses and many more.

Planet Ark does not take responsibility for the accuracy of the original information and encourages readers to check the references before using this information for their own purposes.


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Liam Taylor

Prior to joining Planet Ark Liam spent his time studying global environmental issues, travelling Southeast Asia on the cheap and working for a sustainable property management company in Bali, Indonesia. Joining the communications team at Planet Ark, he hopes to inspire positive environmental behaviour through effective and positive messaging.

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