Fucus guiryi is a brown alga in the family Fucaceae. It is known from numerous locations along the east coast of the North Atlantic Ocean, from Ireland to the Canary Islands.[1]
The species is named in honor of Irish botanist Michael D. Guiry.
The thallus grows to 35 cm long - smaller than other similar species, it is attached by a discoid holdfast. The thallus is flattened and has a midrib like the other common species of Fucus. However it does not have bladders, as Fucus vesiculosus, or serrated edges to the fronds as Fucus serratus nor a twisted thallus, as Fucus spiralis. Fucus ceranoides does not have bladders but may have elongated air pockets in the fronds. The receptacles on F. guiryi show a distinct rim around the edge.[2]
Found growing on rock in the upper mid-littoral.[2]