The plant – which according to researchers is a true ecological mystery – is not only large, but also old: it has already lived through at least 4,500 springs.

You thought cacti could get big? It can be much bigger! Australian researchers have encountered a monster plant in a bay on the westernmost tip of the Australian continent. And this plant is so big, that it has now gone down in the books as the largest plant on earth.

Discovery

Scientists found the plant in the shallow, sun-kissed waters of Australia’s Shark Bay, according to the study, published in Proceedings of the Royal Society B† “When we started our project, we wanted to understand how genetically diverse the seagrass meadows are here,” said researcher Elizabeth Sinclair. “We are often asked how many different plants grow in seagrass meadows.” The researchers took several samples. After analysis, they were amazed. “The answer blew us away,” recalls researcher Jane Edgeloe. “It turned out to be just one plant!”

big and old

It means that the seagrass – known by its scientific name Posidonia australis – extending over an area of ​​no less than 180 kilometers. “This makes it the largest known plant on Earth,” said Edgeloe. The plant is not only gigantic, it is also very old. For example, the researchers estimate that it has already experienced at least 4,500 springs.

Ecological riddle

According to the researchers, the plant is a true ecological mystery. “How it is possible that this plant has lived and bloomed for so long is a mystery,” said researcher Martin Breed. “The plant may be ‘sterile’, meaning it is sterile. Such plants often have reduced genetic diversity, something they normally need to cope with environmental changes.”

Environmental changes

Still, the unruly seagrass seems to hold its ground. “This plant has already experienced many environmental changes,” Breed continues. “Even today it experiences a huge range of varying temperatures: from 17 to 30 degrees Celsius. It has also experienced different salinities and changing light conditions. Such conditions would normally be very stressful for plants. However, it does not seem to affect this plant.”

polyploid

What also makes the plant unique is that it surprisingly has twice as many chromosomes as its oceanic relatives. And that means the seagrass with a difficult word is “polyploid.” “In this case, the new seedling contains 100 percent of each parent’s genome,” Sinclair explains. And this may also explain some things. “Polyploid plants often live in places with extreme environmental conditions, are often sterile, but can continue to grow if left undisturbed,” Sinclair says. “And this is exactly what we see with the giant seagrass.”

Research into the bizarrely large plant continues. For example, scientists have already set up a series of experiments to better understand how seagrass survives and thrives under such variable conditions.