The largest, most humongous plant on the planet is a seagrass meadow in Western Australia's Shark Bay. This meadow, known as Poseidon's ribbon weed or Posidonia australis, is a clone of itself, having expanded over 180km in the bay over around 4,500 years. It's the largest known plant on earth, spanning 77 square miles, and is a hybrid of two diploid 'parent' plants with twice as many chromosomes as it should. Seagrass is the only flowering plant that spends its entire life fully immersed in saltwater, making it an important carbon store and habitat for many different animals. However, the future of this seagrass meadow is uncertain due to a marine heatwave in 2010-2011 that damaged around one-third of the meadow and could have released vast amounts of carbon dioxide into the atmosphere. Protecting seagrass meadows is vital to prevent further damage and loss of these vital ecosystems.
