Fucus serratus L.
Description: Dichotmously branched fronds arising from a small disc via a short stipe; distinct midrib. Plants to 300 mm with terminal, compressed receptacles with warty conceptacles. This is the "Serrated wrack" of the lower shore in the north-eastern Atlantic. It is easily recognised by its saw-toothed frond, and a lack of swollen receptacles (see below).
Habitat: Zone forming on sheltered and semi-exposed shores from about MTL down to about MLWN where it meets the kelp zone.
Distribution: Widely distributed on all coasts of Britain and Ireland. Spain north to Spitsbergen.
Usage: Fucus serratus is used in Ireland and France for the production of seaweed extracts for cosmetics, and for seaweed baths.
Similar species: Fucus vesiculosus generally has paired vesicles and does not have a saw-toothed edge; Fucus spiralis has inflated terminal receptacles with a sterile rim,