My great granny would go to Salthill in Galway during the summer to collect carrageen moss. It is full of Vitamin A, B12 and has calcium and iron.
She would bring it home and use it to make a cough mixture. She would boil it in water and add lemon juice, cloves and honey. It was really good.
Mrs May Callaghan, Great Granny, Clontuskert, Ballinasloe gave me this story.