Description: Thallus erect to 30 cms long, main axis terete with 1 central and 4 pericentral cells and corticated. Either with main axis distinct throughout or with latterals branching pseudodichotomously. Latteral branches narowing at base and apex. Cystocarps ovoid.

Habitat: Common. Epilitoral, epilithic or on artifical materials from rock pools at extreme low littoral to 27 m.

Distribution: Widespread in the British Isles including the Shetlands. Europe: Mediterranean, Portugal, Atlantic coasts of Spain and France, Netherlands, Baltic Sea, Faroes, Norway and Spitzbergen. Greeenland. Atlantic coast of North America: Canada, Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut and Long Island. Further afield: the Canary Islands.

Similar Species: Polysiphon elongella however the cortication is less developed in P.elongella and the ramuli narrow near the base in P.elongata.

Distribution Map from NBN: Polysiphonia elongata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Polysiphonia elongata at iNaturalist World Species Observations database.

WoRMS: Polysiphonia elongata at World Register of Marine Species. Accepted name: Carradoriella elongata (Hudson) Savoie & G.W.Saunders, 2019. AphiaID: 1340378.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Rhodomelaceae; Polysiphonieae; Polysiphonia