Description: A small filamentous algae, growing erect as tufts to 5 cms. Main axis with transverse and longitudinal divisions ending with a large apical cell. Branches variable, abundant and more or less pinnate, opposite.

Habitat: Abundant in the littoral and infralittoral to 12 m, usually epiphytic.

Distribution: Widespread around the British Isles. Europe: Mediterranen, Azores, Atlantic coasts of Spain and France, the Netherlands, Baltic Sea, Norway, Sweden and the Faroes. Atlantic coast of North America: Canada, Maine, Connecticut, New Jersey and Virginia. Further afield: Cumberland Sound in Baffin Bay and coast of Greenland, Canary Island and Cape Verde Islands.

Similar Species: Most species of Sphacelaria and other small branched brown algae are very alike. They require microscopic examination for identification.

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

iNaturalist: Sphacelaria cirrosa at iNaturalist World Species Observations database.

WoRMS: Sphacelaria cirrosa at World Register of Marine Species. Accepted name: Sphacelaria cirrosa (Roth) C.Agardh, 1824. AphiaID: 145892.

Classification: Biota; Chromista; Harosa; Heterokonta; Ochrophyta; Phaeophyceae; Dictyotophycidae; Sphacelariales; Sphacelariaceae; Sphacelaria