A genus of seaweeds, species of which occur in abundance on shores in the northern hemisphere. The branches of the thallus are flattened and have a pronounced thickened midrib. Gametes are formed in conceptacles carried in swollen receptacles at the tips of branches. They are found, often abundantly, in the intertidal zone, attached to rocks etc. See also bladder wrack; serrated wrack; and spiral wrack.
Subjects: Plant Sciences and Forestry.