AppearanceThe thallus of ''C. officinalus'' is firmly attached generally to rock and grows in tufts to a length of 120mm. It has pinnate branching with successive opposite lateral branches. Each frond consists of cylindrical calcified stipes which show segments each a little longer than broad, rising from a crustose base like a string of beads becoming larger and more wedge-shaped higher up the stipe.
It forms calcium carbonate deposits within its cells which serve to strengthen the thallus. These white deposits cause the seaweed to appear pink in colour, with white patches where the calcium carbonate is particularly concentrated, such as at the growing tips. The calcium carbonate makes it unpalatable to most rocky shore grazers.
Distribution''C. officinalis'' is found on solid rock on the North Atlantic coast, from northern Norway to Morocco, and intermittently from Greenland to Argentina. ''Corallina'' is also found in USA, Argentinaand elsewhere including some parts of Japan, China and Australasia.
Habitat''Corallina'' grows on rocks in rock pools and occasionally on shells or other algae, at mid-littoral to 33m deep, it provides a habitat for many small animals which feed on the microorganisms dwelling in its dense tufts.
Some text fragments are auto parsed from Wikipedia.