Seaweeds on the web the most authoritative,  comprehensive, and up-to-date online database on terrestial and marine algae as well as sea grasses from more than 200 countries. The data base contains information on more than 130.000 species, presented along with illustrations and photos as well as geographical distribution and references to the international literature. homepage for The International Seaweed Organization that represents interests in research and industrial applications of algae. a very extensive homepage with general information on algae, aquaculture, and uses of algae as food and medicine. The page has an impressive collection of images of seaweeds. homepage for The Phycological Society of America with comprehensive information and links to museums, collections, and algae by taxa and location around the world.