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seaweed 
Usually aquatic vegetables used in cooking or as dietary supplements; they are primarily produced and eaten by the Japanese.
nori
Purplish alga that turns black when dried; usually sold in thin dried sheets, it is used mainly to make sushi.
dulse
Iron-rich, it has long been eaten by people living along Europe’s coasts; it enhances soups and salads with its soft texture and strong flavor.
agar-agar
Translucent strips derived from red algae, which is melted to produce a jelly that can replace gelatin in numerous recipes.
sea lettuce
Resembles lettuce leaves in taste and appearance; its soft leaves are eaten raw in salads or cooked in soups.
hijiki
These dried twigs expand when soaked, resembling black, somewhat crunchy noodles; they are often served as a vegetable.
