Fucus spiralis is an intertidal brown seaweed with fronds, often twisted, that has a characteristic ridge along the receptacles’ edge. Usually found attached to rock substrata on sheltered to moderately exposed shores, these species can tolerate a high level of desiccation which allows them to live up to 4 years. (Nicola White 2008. Fucus spiralis. Spiral wrack. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 19/11/2013])

Their reproductive bodies form eliptic structures with a swollen appearance named conceptacles. (Pereira, L.;Guia Ilustrado das Macroalgas: Conhecer e reconhecer algumas espécies da flora portuguesa; 1ª edição, Coimbra; 2009). F. spiralis is common on the coasts around the British Isles, and the western coast of Europe, Canary Islands and North-eastern America. (M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 19 November 2013.)