Description: Thallus calcareous, articulated, branching from a crustose base to a hight of about 12 cms. Branches pinnate or irregular.

Habitat: Abundant and dominant in some rock pools of the littoral and in the sublittoral to at least 18 m. Epilithic.

Distribution: All around the British Isles. Europe: Azores, Portugal, Spain, Netherlands, Baltic Sea, Norway, Faroes and Iceland. Greenland. Atlantic coasts of North America from Labrador south to Connecticut and Maryland. Further afield: Arctic Sea, Canary Islands and South Africa.

Similar Species: Corallina elongata and Haliptilon squamatum.

Key Identification Features:

• The most common calcareous alga with articulated fronds.

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

iNaturalist: Corallina officinalis at iNaturalist World Species Observations database.

WoRMS: Corallina officinalis at World Register of Marine Species.