The common name for the brown seaweed Laminaria saccharina. The thallus consists of a branched, root-like holdfast, a smooth, slender stipe, and a yellowish-olive frond which is single and ribbon-like with an undulating central region and frilly margins. When dry, a whitish, sweet-tasting deposit sometimes appears on the surface of the fronds, hence the alternative name of sugar kelp. Another alternative name is poor man's weather-glass, since under humid conditions the fronds remain soft and limp, whereas under dry conditions they become hard and brittle.
Subjects: Plant Sciences and Forestry.