Description: Plants tufted no more than 15 mm long. Consisting of filaments, monosiphonous at the base and polysiphonous above.

Habitat: Rare. Epiphytic on algae and Zostera in the lower littoral and upper sublittoral.

Distribution: Gererally a southern species, however has been recorded from the Shetlands and the north of Ireland. Europe: Mediterranean, Portugal, Atlantic coast of Spain and France, Baltic Sea and Norway. Atlantic coast of North America: Canada and Massachusetts. Further afield: the Canary Islands.

Similar Species: Similar to other small tufted algae, requires microscopic examination for identification.

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

iNaturalist: Giraudia sphacelarioides at iNaturalist World Species Observations database.

WoRMS: Giraudia sphacelarioides at World Register of Marine Species.