Class phaeophyceae
Organisms of highly variable organisation, but always multicellular, from branched filamentous species to highly complex species differentiated into haptera, stipe and frond. They present chlorophylls a and c, green-coloured pigments, and a large quantity of fucoxanthin, a brown-coloured pigment responsible for their characteristic colouring. As a storage product they contain lamarin. In the cell walls there are colloidal substances (alginates) which are used in industry. They are marine organisms, with the exception of a few species that live in freshwater, and they are more abundant in cold and temperate seas where they can form submarine forests.
