Syn. Cystoseira abrotanifolia subsp. pustulata Ercegović 1952
Thallus often caespitose, up to 1 m tall. Algae is pyramidal in form and greenish in coloration during spring when fully grown and fertile. While easily confused with C. compressa, its branches are much more cylindrical, and the axis is much longer (up to a few cm).
Intertidal and shallow subtidal. Often in moderately exposed areas. Occasionally found in tide pools.
Widespread and common, it is mostly found in mixed fucalean forests, where it cohabits with similar C. compressa.