Unidentified seaweed, Lyme Regis

Unidentified seaweed, Lyme Regis

Observation - Unidentified seaweed, Lyme Regis - UK and Ireland. Description: A very dark brown seaweed, but from the strandline fairly high up the beach so may be discoloured. B

A very dark brown seaweed, but from the strandline fairly high up the beach so may be discoloured. Branching at least tri-pinnate. Has intercalary pea-sized air vesicles, supposedly a key characteristic for Cystoseira baccata on http://www.seaweed.ie/descriptions/Cystoseira_baccata.php. See pencil for scale. The main stem is very tough and stem/main branches have a zigzagging main axis.