Fucus serratus is a seaweed

Seaweed

Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...

 of the north Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

, known as toothed wrack or serrated wrack.  It is olive–brown in colour and similar to F. vesiculosus

Bladder wrack

Fucus vesiculosus, known by the common name bladder wrack or bladderwrack, is a seaweed found on the coasts of the North Sea, the western Baltic Sea, and the Atlantic and Pacific Oceans, also known by the common names black tang, rockweed, bladder fucus, sea oak, black tany, cut weed, dyers fucus,...

and Fucus spiralis

Fucus spiralis

Fucus spiralis is a species of seaweed, a brown alga , living on the littoral shore of the Atlantic coasts of Europe and North America. It has the common names of spiral wrack and flat wrack.-Description:...

. It grows from a discoid holdfast

Holdfast

A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. ...

. The fronds are flat, about 2 cm wide, bifurcating, and up to 1 m long including a short stipe

Stipe (botany)

In botany, a stipe is a stalk that supports some other structure. The precise meaning is different depending on which taxonomic group is being described....

. It branches irregularly dichotomously. The flattened blade has a distinct midrib and is readily distinguished from related taxa by the serrated edge of the fronds. It does not have air vesicle

Vesicle (biology)

A vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of many different molecules. More technically, a vesicle is a small membrane-enclosed sack that can store or transport substances. Vesicles can form naturally because of the properties of lipid membranes , or...

s, such as are found in F. vesiculosus, nor is it spirally twisted like F. spiralis.

The reproductive bodies form in conceptacles sunken in receptacles towards the tips on the branches. In these conceptacles oogonia

Oogonium

"Oogonium" may refer to either a primordial oocyte in a female fetus or the female gametangium of certain thallophytes.-in the fetus:Oogonia are formed in large numbers by mitosis early in fetal development from primordial germ cells...

 and antheridia are produced and after meiosis

Meiosis

Meiosis is a special type of cell division necessary for sexual reproduction. The cells produced by meiosis are gametes or spores. The animals' gametes are called sperm and egg cells....

 the oogonia and anteridia are released. Fertilisation follows and the zygote

Zygote

A zygote , or zygocyte, is the initial cell formed when two gamete cells are joined by means of sexual reproduction. In multicellular organisms, it is the earliest developmental stage of the embryo...

 develops, settles and grows directly into the diploid sporophyte

Sporophyte

All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or algae that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants...

 plant.

Distribution and ecology

Fucus serratus is found along the Atlantic coast of Europe from Svalbard

Svalbard

Svalbard is an archipelago in the Arctic, constituting the northernmost part of Norway. It is located north of mainland Europe, midway between mainland Norway and the North Pole. The group of islands range from 74° to 81° north latitude , and from 10° to 35° east longitude. Spitsbergen is the...

 to Portugal

Portugal

Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

, in the Canary Islands

Canary Islands

The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...

 and on the shores of north-east America

Americas

The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

.  It was introduced to Iceland

Iceland

Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

 and the Faroes by humans within the last 1000 years where it was first noted in a phycological survey in 1900. It grows very well on slow draining shores where it may occupy up to a third of the area of the entire seashore.  It often dominates the rocky parts of the lower shore, exposed or immersed in rock pools, on all but the most exposed shores.  “…the littoral zone is characterized especially by such phaeophyta (brown algae) as Ascophylluym, Egregia, Fucus

Fucus

Fucus is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world.-Description and life cycle:...

 and Laminaria

Laminaria

Laminaria is a genus of 31 species of brown algae , all sharing the common name "kelp". This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are referred to by the common name Devil's apron, due to their shape, or sea colander, due to...

, particularly when the shore is rocky."

Uses

F. serratus is used in Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 and France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 for the production of cosmetics

Cosmetics

Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...

 and for thalassotherapy

Thalassotherapy

Thalassotherapy is the unproven medical use of seawater as a form of therapy. The properties of seawater are believed to have beneficial effects upon the pores of the skin. Thalassotherapy was developed in seaside towns in Brittany, France during the 19th century...

. In the Western Isles of Scotland, it is harvested for use as a liquid fertiliser.