How often have we wondered what those soft, felt-like, vegetal balls that we find on the beaches and along the coasts are?

Often called sea balls, sea rissols or sea potatoes, they are the result of leaves of oceanic posidonia that have torn up.

The leaves of oceanic posidonia are ribbon-like and can reach a length of 1 metre, are green in colour when young but when old they come off the plant and turn brown. Once they are dead, thanks to weather and sea conditions, what remains of the fibre-like leaves of the posidonia that are at the base of the rhizomes (or stems )cluster together very closely and create these characteristic, brown coloured balls that can vary in size.

Left on the shore by the waves, once they are completely dry, the wind blows them all along the coast.

Their scientific name is egagropili.