Description: Thallus to 30 cms long, soft with irregular branches, central medulla of elongate cells, a narrow cortex with short assimilatory cells.

Habitat: Not uncommon. Low littoral.

Distribution: Generally western, Cornwall, west Ireland with a few records from the east and west coasts of Scotland. Europe: Mediterranean, Atlantic coast of France, Baltic Sea and Norway. Atlantic coast of North America: Canada, Massachusetts, Rhode Island, Connecticut and Long Island, New Jersey and Virginia. Further afield: the Canary Islands.

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

iNaturalist: Stilophora tenella at iNaturalist World Species Observations database.

WoRMS: Stilophora tenella at World Register of Marine Species.