Seaweed

Seaweed refers loosely to any of a large number of marine algae considered by phycologists to be macrothallic (large-bodied), differentiated from most algae that tend towards microscopic size. Seaweeds are found among the green, red, and brown algae. Some cyanobacteria may also be counted as seaweeds.

Seaweeds are named after terrestrial weeds, and are not to be confused with things like seagrass which are vascular plants.

Table of contents

1 Structure 2 Uses 3 External Link

Structure

Seaweeds may have an appearance that resembles a non-arboreal terrestrial plants.

• frond or thallus: the algal body
  • blade: a flattened structure that is somewhat leaf-like
    • sorus: spore cluster
    • on Fucus -- Air bladders: float-assist device (on blade)
    • on kelp -- floats: float-assist device (in between blade and stipe)
  • stipe: a stem-like structure
  • holdfast: specialized basal structure providing attachment to the bottom

Seaweeds are used extensively as food by coastal peoples, most particularly in Japan but also in Korea, in Peru and in the Canadian Maritimes. For example, nori is a dried red alga, formed into sheets, and used to wrap sushi. Irish moss is another red alga used in producing various food additives. Other seaweeds may be used as seaweed fertiliser.

External Link

• The Seaweed Site, information on all aspects of seaweeds and marine algal biology