Common Coral Weed belongs to a group of red seaweeds known as coralline seaweeds, they have a chalky deposit in their cell walls that makes them hard. Coral weed fronds have sections that are ridged but separated by a flexible joint that allows them to move with the wave action.
The branches usually lie flat creating a flattened frond, but the shape of these plants can be quite varied.
On the open shore, the fronds grow in a short mat about 5 cm high but reach heights of up 15 cm in protected areas and rock pools. Common Coral Weed gardens are great places for small animals and other small seaweeds that attach themselves to the fronds.
Below the low tide line, the fronds can grow much longer. The color of coral weed varies from dark purple when it lives in the shade to light pink in sunny locations. When the seaweed dies, its hard skeleton turns bone white before disintegrating to become a part of the sand that makes up the shoreline.