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.