noun, singular: brown alga
Brown algae are algal species characterized by their brown or greenish brown color. Their color is due to the presence of brown pigments, e.g. fucoxanthin, in addition to chlorophyll. Many of them are macroscopic. In fact, kelps are large brown seaweeds that grow in shallow oceans and form the so-called kelp forest. Fucus is another macroscopic brown algal species. They thrive in intertidal zones of rocky seashores. They are harvested, dried, and processed for the commercial production of soap, glass, etc. They are also used as fertilizers.
Brown algae belong to Phylum Phaeophyta. In the old scheme of classification, i.e. the five kingdom scheme, Protista is a kingdom comprised of animal-like (protozoa), plant-like (algae), and fungus-like (slime molds and water molds) organisms. Accordingly, Protista is divided into several phyla. The plant-like or algal species are further divided into the following phyla: Euglenophyta, Chrysophyta (diatoms), Pyrrophyta (dinoflagellates), Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae).1 Recent studies and findings, though, would lead to changes in the taxonomic positions and to newer systems of classification.2 Nevertheless, Phaeophyta is a clade comprised of organisms commonly referred to as brown algae. These organisms are important as food and as habitat for many aquatic animals.
1 Pascher, A. (1914). "Über Flagellaten und Algen ". Berichte der deutsche botanischen Gesellschaft 32: 136–160. 2 The NCBI taxonomy database. Retrieved from .