The plant is densely bushy and grows up to 15cm high. It has short hairy branchlets, which are often curled. It is dark brown to purple and can bleach to golden brown.

Moss seaweed forms dense bands at mid to high tide on exposed shores. It provides habitat for many intertidal animals such as Horn snails. The dense seaweed aids water retention.

Uses the sun's energy for photosynthesis.

Seaweeds of NZ; Adams