Plants usually solitary, 1 m or more in length, attached by a thick, conical attaching disc. Axis simple or branched, up to 1 m in length, flattened, about 1 x 0.4 cm in transverse section; apex smooth and surrounded during periods of active growth by incurred young laterals. Lateral branch systems distichous, alternate, radially symmetrical, profusely branched in a repeatedly pinnate fashion and bearing sparse, filiform, occasionally bifurcate appendages on the branches of higher orders; deciduous, leaving decurrent bases which give an irregular, zigzag outline to the axis. Cryptostomata lacking. Aerocysts present in axes of branches of higher order, sometimes in chains; seasonal, particularly numerous in autumn. Receptacles 1-5 cm long, formed from axes of ultimate ramuli, irregularly nodose and bearing simple, filiform appendages.

Key characteristics: Intercalary pea-sized air vesicles, sometimes in chains.

Link for Algaebase

Loiseaux-de Goër, S. & Noailles, M.-C. (2008). Algues de Roscoff. pp. [1]-215, col. figs. Roscoff: Editions de la Station Biologique de Roscoff.

Sánchez, I., Fernández, C. & Arrontes, J. (2005). Long-term changes in the structure of intertidal assemblages following invasion by Sargassum muticum (Phaeophyta). Journal of Phycology 41: 942-949.

Basionym: Fucus baccatus S.G.Gmelin

Type locality: “Scheuelingensi prope Hagam (Schevelingen, Den Haag, The Netherlands) (Gmelin 1768: 90). Type: original illustration