Posidonia australis

Posidonia australis, also known as fibre-ball weed or ribbon weed, is a species of seagrass that occurs in the southern waters of Australia. It forms large meadows important to environmental conservation. Balls of decomposing detritus from the foliage are found along nearby shore-lines. In 2022, a single stand in Shark Bay was reported by scientists to not only be the largest plant in the world, but the largest organism by square size.