General Sherman is the largest tree in the world. It’s a giant sequoia in Sequoia National Park standing at 275 feet, nearly the length of a football field. It turns out, though, that General Sherman isn’t the biggest plant on earth. 

Scientists have discovered a patch of seagrass off the coast of Australia which is in fact one plant and three times the size of Manhattan. 

Ribbon weed

This enormous seagrass meadow was found in Shark Bay, about 500 miles north of Perth on the western coast of Australia. The scientific team stumbled on the meadow by accident while researching the genetic diversity of seagrass. This is also known as ribbon weed and grows along with many parts of Australia’s coasts. 

The seagrass covers an area of 77 square miles, according to researchers from the University of Western Australia. Their research is published in the journal Proceedings of the Royal Society B. This huge expanse of underwater vegetation has also spawned from a single seed over the last 4,500 years. Researchers found this out when they genetically tested the seagrass and discovered they are all one plant. 

They collected shoots of seagrass from all over Shark Bay, examining 18,000 genetic markers to create a “fingerprint” from each sample. They wanted to see how many plants there were in the meadow. 

“The answer blew us away – there was just one!” said Jane Edgeloe, the study’s lead author. “That’s it, just one plant has expanded over 180km in Shark Bay, making it the largest known plant on Earth.”

The ribbon grass is also very hardy, helping it expand 35cm a year over 4,500 years. It can stand varying degrees of salinity, a range of temperatures, and little light, very difficult conditions for most plants. 

While General Sherman is almost as tall as a football field is long, the Shark Bay seagrass is would cover about 20,000 football fields.