The Neptune Grass (Posidonia oceanica)




You may have found some strange small balls of odd matter on the beach in Mallorca, or if you haven’t, your children may have played with them or your grandchildren.

Be that as it may, in case you wondered, they are a waste-product of the Posidonia Oceanica which is a sea grass and a very important one at that. The Posidonia grass is not an algæ. Instead it belongs to the plant class of Liliopsidas. The grass blades grow to a length of 100 cm and in a depth of up to 40 m deep. The plant forms undersea meadows, some of which quite large.

The Posidonia only grows in clean unpolluted water and is considered by scientist an infallible testimony to a healthy marine environment. The sea grass is called the lung of the Mediterranean as it absorbs up to 16 litres of carbon dioxide per square metre/day. We are lucky here in the Balearic islands to have such a large existence of this important plant. Let’s hope it will remain so for a very long time. But the plant is already considered a threatened species requiring protection.



Anyway, the balls or ægagropiles are created from the debris of the dead Posidonia leaves and other seabed matter, and are formed by the waves into small ball shaped specimen for your or your children’s enjoyment.

The main photo was borrowed from the Internet, courtesy of M.A.P.A., the Spanish Ministry of Agriculture, Fisheries and Food. Muchas gracias to them.

~ by plantarium on December 27, 2007.

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