''Polysiphonia elongata'' is a small red marine algae in the Rhodophyta.

Description

''Polysiphonia elongata'' is a small

red alga Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...

which, unlike some other species of ''

Polysiphonia ''Polysiphonia'' is a genus of filamentous red algae with about 19 species on the coasts of the British Isles and about 200 species worldwide, including Crete in Greece, Antarctica and Greenland. Its members are known by a number of common names ...

'', does not grow as tufts. It has erect cylindrical main branches and is densely branched growing to a height of 30 cm. The main branches bear lateral branches, each branch consists of a central axes of cells with four periaxial cells. These periaxial cells are arranged in an elongated manner all of the same length around the central axial cells. Cortical branches develop growing downwards in the grooves between the periaxial cells and increasing the thickness of the major branch. The final branches are pointed at the apex and attenuate at their base.Bunker, F. StP.D., Maggs, C.A., Bunker, A.R. 2017. ''Seaweeds of Britain and Ireland.'' Second Edition. Wild Nature Press, Plymouth. Trichoblasts are few. It grows attached by a disk-like holdfast.Maggs, C.A. 1993 ''Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales.'' HMSO

Habitat

''P. elongata'' grows

intertidal The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

ly and

sublittoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal area ...

ly on rock,Hardy, F.G. and Guiry, M.D. 2003. ''A Check-list and Atlas of the Seaweeds of Britain and Ireland.'' The British Phycological Society. stones and artificial material also on other algae.

Reproduction

The plants are dioecious. Spermatangial branchlets are borne near the apices of young branches.

Cystocarp A cystocarp is the fruiting structure produced in the red algae after fertilization, especially such a structure having a special protective envelope (as in '' Polysiphonia)''. The structure from which carpospore A carpospore is a diploid spore p ...

s are ovoid and slightly stalked.

Tetraspore Tetraspores are red algae spores produced by the tetrasporophytic (diploid) phase in the life history of algae in the Rhodophyta as a result of meiosis.Jones, W.E. Revised and reprinted 1964. A Key to the genera of the British seaweeds.''Field Stu ...

s occur in spiral series in the upper branches.

Distribution

''P. elongata'' is common around

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

,Morton, O. 1994.''Marine Algae of Northern Ireland.'' Ulster Museum,

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It i ...

including the

Channel Islands The Channel Islands ( nrf, Îles d'la Manche; french: îles Anglo-Normandes or ''îles de la Manche'') are an archipelago in the English Channel, off the French coast of Normandy. They include two Crown Dependencies: the Bailiwick of Jersey, ...

, the

Isle of Man ) , anthem = "O Land of Our Birth" , image = Isle of Man by Sentinel-2.jpg , image_map = Europe-Isle_of_Man.svg , mapsize = , map_alt = Location of the Isle of Man in Europe , map_caption = Location of the Isle of Man (green) in Europe ...

and the Shetland Islands. In the Atlantic from

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...

to the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...

and in

New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the Can ...

References

{{Taxonbar, from=Q30594174 Rhodomelaceae