Back in April, we debunked the myth that the blue whale/the redwood forest/elephants/ [add your favourite humongous animal or plant] are the largest living organisms on the planet.  We reported that the largest (living) organism is a single gigantic specimen of honey mushroom (Armillaria ostoyae), discovered in the Malheur National Forest, Oregon, USA, in 1998. It occupies a total area of almost 10 square kilometres, equivalent to 1,350 soccer fields, and possibly weighs as much as 35,000 tons, making it the world’s most massive living organism.  Well, no more.

Recently, scientists have discovered a hybrid seagrass that extends for an astonishing 180km across Australia’s Shark Bay, making it the largest known organism on Earth. It covers approximately 200 square kilometres – equivalent to around 28,000 soccer fields or more than 450 times bigger than Vatican City, the world’s smallest country.   

Researchers found that it spawned from a single seed, and based on this species’ growth rate (15 to 35cm per year), it is estimated to be around 4,500 years old. It has spread over the millennia via underground clonal shoots known as rhizomes, meaning that the entire plant is connected and shares the same DNA, though the authors of the study note that certain patches (ramets) in a clonal plant do become separated over time so gaps can emerge.