The world’s largest plant has recently been discovered off the West Coast of Australia: a seagrass 180 km in length.

But stretching across 150 km — which is about the distance between Mumbai and Pune – is not even the only remarkable thing about the plant.

The ribbon weed, or Posidonia australis, has been discovered in Shark Bay by a group of researchers from Flinders University and The University of Western Australia. These researchers have also found that the plant is 4,500 years old, is sterile, has double the number of chromosomes than other similar plants, and has managed to survive the volatile atmosphere of the shallow Shark Bay.

So how remarkable is this plant’s size?

The ribbon weed covers an area of 20,000 hectares. The next on the podium, the second largest plant, is the clonal colony of a quaking Aspen tree in Utah, which covers 43.6 hectares. The largest tree in India, the Great Banyan in Howrah’s Botanical Garden, covers 1.41 hectares.

If it is so large, how come it has just been discovered?

The existence of the seagrass was known, that it is one single plant was not. Researchers were interested in what they then thought was a meadow because they wanted to study its genetic diversity, and collect some parts for seagrass restoration.

The University of Western Australia quotes UWA student researcher and lead author of the study, Jane Edgeloe, as saying that the team “sampled seagrass shoots from across Shark Bay’s variable environments and generated a ‘fingerprint’ using 18,000 genetic markers.”

“The answer blew us away – there was just one!” Edgeloe was quoted as saying. “That’s it, just one plant has expanded over 180km in Shark Bay, making it the largest known plant on earth.”

The findings were published in the journal Proceedings of the Royal Society B.