Nori, wakame and kombu are seaweeds used in Japanese cooking.
Nori is the thin black sheets that are used to wrap sushi rolls.
Wakame is a dark green, fern-like seaweed. It is used mainly in soups (particularly miso soup) and salads. It needs to be soaked before use and stored in a cool, dry place.
Kombu is a ribbon like plant that is folded before being sun-dried. It is used in stocks and boiled dishes. It is rich in flvour enhancing glutamic acid which prompted the development of monosodium glutamate.