On the picture you can see a shoot of Posidonia oceanica also known as Neptune grass – a seagrass species in the Mediterranean Sea. A related seagrass species is the world’s largest living plant – but not because of it’s shoot length. Researchers recently discovered that a single species of Posidonia australis stretched over an area of 180 kilometers in Shark Bay, Australia. This single plant is so large because it clones itself by spreading via its rhizome – a continuously growing horizontal underground stem that sends out roots and shoots from its nodes.
More exciting information about seagrass as well as photos, videos and a children's book can be found here: