Description: Thallus of erect filaments, narrow and cylindrical, in tufts to 20 cms long without whorl-branches. Branching pseudodichotomously to 20 cms long.

Habitat: Common. Epilithic and epilithic in pools at low-littoral and sublittoral to 10 m.

Distribution: Generally distributed around much of the British Isles including the Shetlands and the Channel Islands. Europe: Mediterranean, Atlantic coast of Spain, Netherlands, Faroes and Norway. Further afield: Morocco.

Similar Species: Griffithsia devoniensis does not have whorles of branches, is not so rigid and grows to only 5 cms.

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

iNaturalist: Halurus flosculosus at iNaturalist World Species Observations database.

WoRMS: Halurus flosculosus at World Register of Marine Species.