Description: Main axis with transverse and longitudinal divisions ending with a large apical cell. 1 to 2 cms high with opposite branching, pinnate.

Habitat: Not uncommon. Epilithic and epizoic on Pecten in the sublittoral 12 to 18 m.

Distribution: Scattered records around the north-western shores of the British Isles including the Shetlands. Europe: Azores, Portugal, Atlantic coasts of Spain and France, Netherlands, Baltic Sea, Norway. Atlantic coast of North Americe: Canada. Further afield: the Canary Islands.

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

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

iNaturalist: Sphacelaria plumula at iNaturalist World Species Observations database.

WoRMS: Sphacelaria plumula at World Register of Marine Species. Accepted name: Sphacelaria plumula Zanardini, 1864. AphiaID: 145898.

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