World's largest plant found off Australian coast

Researchers from the University of Western Australia and Flinders University discovered off the coast of Western Australia, the seaweed colony Posidonia australis, which covers a total of 200 km². This whole ecosystem has grown from just one sprout, which makes it the largest plant in the world.

The find turned out to be accidental. The scientists wanted to study the genetic diversity of the seagrass meadows in the Shark Bay area. They sampled shoots from across the region in several different environments and then examined 18,000 genetic markers to create plant profiles.

The results of the work done amazed them - all the collected samples turned out to be part of one plant, which has grown more than 180 km. The entire meadow appears to have been formed from a single colonizing plant, the scientists noted.

These seaweeds clearly claim the record, at least in terms of area. The previous largest plant record was a clonal colony of aspen poplar in Utah, nicknamed Pando. There, a whole grove of aspens grew from one tree and is connected by one root system. The area of ​​the ecosystem is only 0.4 km². But at the same time, Pando is likely to be larger in terms of biomass.

In any case, the giant seaweed meadow has other claims to fame. The team calculated that it is at least 4,500 years old and figured out how it manages to cope with environmental changes despite the lack of genetic diversity. It turned out that this is a polyploid plant, that is, it actually contains two complete genomes of parent plants, and not one part of it.

Now the team of scientists plans to continue researching the plant to uncover more of its secrets.