Phylum: Rhodophyta   Family: Dumontiaceae

Dumontia contorta (S.G. Gmelin) Ruprecht, 1850

Dumont's Tubular Weed

A common seaweed of the mid to lower tidal zones. Unusually, it starts into grown in the autumn, attaining a length of up to half a metre by spring

References: 
Newton (1931) - A Handbook of the British Seaweeds;
Bunker, et al - Seaweeds of Britain and Ireland