The main stems (stipes) are flattened and broadly sinuose and have blades of different forms, those near the base of the plant are larger with a distinct, wide midrib. The upper blades are long and narrow and during the fertile phase each alternate one has bunches of receptacles for reproductive material. It has vesicles (gas bladders) which are rounded with a sharp point. The holdfast is flattened and creeping. The colour is dull, dark brown and the texture leathery except for the blades which can be brittle.

Found in sheltered waters with good currents. Great seaweed for pipefish and seahorses to camouflage in.

Uses the sun's energy for photosynthesis.

Common relative of the seaweed known as "wrack" in Britain."

CommonSeaweeds: Adams