Any of various brown, often very large seaweeds that grow in colder ocean regions. Kelps are varieties of brown algae of the order Laminariales, with some species growing over 61 m (200 ft) long. Kelps are harvested as food (primarily in eastern Asia), as fertilizer, and for their sodium and potassium salts, used in industrial processes. Kelps are also a source of thickening agents and colloid stabilizers used in many commercial products. See more at
brown alga.