This is a large brown seaweed of up to 1-3 m long made up of a holdfast, much branched stems and leaf-like blades. Numerous air vesicles are present to give buoyancy to the plant. The leaves are of varying shapes and sized, within the species as well as between species. The sexual organs are confined to specialised structures, the finger-like receptacles. The sex organs are found buried inside circular cavities, the conceptacles, in the receptacles. The conceptacles carry both male (antheridia) and female (oogania) organs or either male or female organs.
Distributed throughout the warm seas of the world.
Sargassum is harvested as a source of phycolloides, particularly alginates, used in the textile industry mainly in Indonesia and the Philippines. The tender parts of the plant is eaten raw as a salad or cooked with coconut milk in various dishes. The plants are also used as a soil conditioner after decomposition or made into seaweed meal fertiliser. It is also used to produce biogas and animal feeds. In Chinese traditional medicine, it is used to treat goitre, scrofula, urinary problems and dropsy. In the Philippines it is used to control blood cholestrol level while in Indonesia it is used to treat urinary diseases and goitre.