Ceramium shuttleworthianum (Kützing) Rabenhorst
Description: Densely tufted,dark purple fronds, to 150 mm long, repeatedly dichotomous, of uniform diameter throughout. Axils wide, apices strongly inrolled. Articulations corticated at nodes, each node with 3-celled, short, pigmented spine on outer side.
Habitat: On rock, on mussels and epiphytic, intertidal, on exposed shores
Photographs © M.D. Guiry