Description: Thallus filamentous and very delicate, prostrate axes become erect at the tips to a height of 15 cms, densely branched, in whorls or complanate in opposite pairs and tufted.

Habitat: Epiphytic, epizoic and epilithic from low littoral to 15 m deep.

Distribution: Generally a northern species. Recorded from Ireland, England and Scotland including the Shetlands. Europe: Faroes, Norway and Iceland. Greenland. Atlantic coast of North America: Canada to Massachusetts. Further afield: Baffin Sea.

Similar Species: Other species of Antithamnionella .

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

iNaturalist: Antithamnionella floccosa at iNaturalist World Species Observations database.

WoRMS: Antithamnionella floccosa at World Register of Marine Species. Accepted name: Antithamnionella floccosa (O.F.Müller) Whittick, 1980. AphiaID: 144520.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Ceramiaceae; Ceramioideae; Dohrnielleae; Antithamnionella