Marine Animal Encyclopedia
Coral weed Corallina officinalis
Coral weed belongs to a group of red seaweeds known as coralline seaweeds, which have chalky deposits in the cell walls that give them a hard structure. Coral weed fronds have rigid sections that are separated by flexible joints. The branches usually lie in one plane, forming a flat, featherlike frond, but the shape is very variable. On the open shore, the fronds are often stunted, forming a short mat a few inches high in channels and rock pools and on wave-exposed rocks. Coral weed mats often harbor small animals, and other small red seaweeds attach to the hard fronds. Subtidally, the fronds grow much longer. The color of coral weed varies from dark pink when it lives in the shade to light pink in sunny locations. When the seaweed dies, its hard skeleton becomes part of the sand.