Did you know plants grew in the sea? Can you think of any? Yes, that's right: seaweed. There are lots of different types and they are all algae. Some seaweeds, called kelp, are enormous. Japanese people eat a lot of seaweed - a good idea since it's full of vitamins and minerals. It even tastes good - I know, I've tried it! And did you know that there are even plants which flower in the sea? They are called sea grass (Posidonia) and grow in the Mediterranean Sea.