A honey mushroom in Oregon is no longer the world’s largest living thing. Guinness World Records updated that title thanks to new research in Shark Bay, Western Australia. A clonal seagrass now holds the record. At 77 square miles, it far exceeds the 0.2 square mile fungus. It’s a 4,500-year-old colony where every blade is a clone.

Seagrass with green and purple stems underwater in Shark Bay, Western Australia
Rachel Austin/University of Western Australia

Clonal seagrass is also known in the Mediterranean Sea. A nine-mile cluster there may be as much as 200,000 years old. Shark Bay is a relatively new body of water in comparison.

The plant is called Poseidon’s ribbon weed. Researchers studying the diversity of seagrass in Shark Bay made the discovery, which we saw on Live Science. Instead of diversity, they found that most of the plant life is genetically identical.

It’s an adaptation that makes the seagrass more hardy. Living in shallow water means it’s more vulnerable to climate change and storms. But cloning itself helps it survive longer in these conditions.

“Even without successful flowering and seed production, it appears to be really resilient, experiencing a wide range of temperatures and salinities plus extreme high light conditions, which together would typically be highly stressful for most plants,” the study’s lead author Dr. Elizabeth Sinclair said in a press release. The peer-reviewed journal Proceedings of the Royal Society B published the study. 

Angela Rossen/University of Western Australia

A cluster of quaking aspen in Utah likely remains the world’s largest organism by weight. Though taking up less than 0.2 square miles, aspen trees are much heavier than seagrass. Other than fossils that may actually be alive, the aspen trees are also one of the oldest living organisms. It’s good to know Guinness World Records is keeping tabs on this and other important natural wonders.

Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.