Seaweed
"Seaweed" is a colloquial term and lacks a formal definition. A seaweed may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. As these three groups do not have a common multicellular ancestor, the seaweed are in a polyphyletic group. In addition, some tuft-forming bluegreen algae (Cyanobacteria) are sometimes considered to be seaweed.
Wakame
, "Undaria pinnatifida", is a species of edible seaweed, a type of marine algae, and a sea vegetable. It has a subtly sweet, but distinctive and strong flavour and texture. It is most often served in soups and salads.