Members of this small genus of seaweeds are often seen washed up on the shores of beaches. Commonly called wracks, Fucus has a brown mossy appearance and a typical salty sea-like smell. Some species may have health benefits, which although not scientifically proven, are frequently advertised as key components in nutritional supplements.
The term seaweed is loosely applied to the many plants found growing in the oceans. Seaweeds, however, are not weeds at all, but marine algae. Marine algae are different from the plants that grow on land because they lack many of the structures typically associated with their terrestrial cousins, such as roots, stems, leaves, and flowers. Yet, both land plants and seaweed are capable of converting the sun's energy into food through the process of photosynthesis. In Fucus and other large brown seaweeds, a structure called the bladecontains the specialized cells needed to perform this function. The blade often has a gas bladder, termed a pneumatocyst, attached to it that helps keep the plant near the surface of the water so it can get the sunlight needed for photosynthesis.
Seaweeds have long served a multiplicity of purposes for man. Mediterranean seaweeds were employed as fodder and as herbal medicine in ancient Greece and Rome. Reports indicate that they may have been used even earlier in China and Japan. Today, seaweeds are used for food, cosmetics, soaps and a wide range of other products. Some Fucusseaweed species are especially popular as of late due to their high iodine content. Iodine is believed to have the ability to stimulate the thyroid gland and, therefore, promote weight loss. Studies, nevertheless, have not provided any conclusive evidence that Fucus has special nutritional benefits, so buyers should beware.