My Name is Posidonia

My name is Posidonia. Oceanic Posidonia. My home is the Mediterranean sea. Yes, I live under water ! I live under water, but let’s be clear, I am not an algae, I am a plant. My body is made of strong roots, rhizomes, and very beautiful light green leaves which can be up to one meter (3’4’’ feet) long.

foto 1 posidonia sketch eng

In order to grow, I look for sandy sea grounds where I can set my roots, then I start colonizing the sea ground thanks to my rhizomes. Like every plant I eventually make a beautiful flower. I do this in September, when you go back to school. Then in March, I turn my flowers into fruits that truly look like small olives. When falls comes into the sea world, I will lose my leaves, which will float and drift to the beaches and they form so-called « banquettes ».

foto 2 banquette
These are “banquettes”. Strange word, French word.


When I thrive, I create marvellous and magic underwater places. They are called Posidonia pastures. It is all green, it is beautiful there. These pastures that I create are very important for the Mediterranean sea. Now I will explain to you why.

foto 3 prateria posidonia
This pasture could be called a field.


First of all, you can compare me to a sea tree. My pastures are exactly like a forest. What does it mean ? It means that I make the oxygen that enables all the underwater animals to breathe and live. Besides a few fishes really love my leaves and often chew some of them. You can see it on some leaves. Plus I slow down the waves and, by doing so, protect the coast from the erosion.

Last but not least, my pastures are a real castle where you can find so many inhabitants. A life that you cannot imagine thrives in my pastures. I am the bigger fishes’ hunting field, while smaller fishes use my leaves to hide. Others also use me to hide their eggs from hungry predators…

There are big shells between my rhizomes and my leaves, and deeper you go, the more species you find. There is something different and magic at very floor.

I am like the sea world: there are different forms of life that live together between my leaves…

Kids, if you see sometimes while you are swimming, be kind, don’t tear me off the ground.

foto 4 vita vicino alla posidonia
I am full of life.