• (a.) Pertaining to seaweeds of the genus Laminaria, or to that zone of the sea (from two to ten fathoms in depth) where the seaweeds of this genus grow.
Lam`i·na'ri·an adjective Pertaining to seaweeds of the genus Laminaria, or to that zone of the sea (from two to ten fathoms in depth) where the seaweeds of this genus grow. 
scale, thin layer) the true kelps of the order Phaeophycea: giant kelp, stalked kelp