Plant
Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom. The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the brown, red and green algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, and they are no longer classified as plants as defined here.
Wildlife of Antarctica
Other algae live in or on the sea ice, often on its underside, or on the seabed in shallow areas. Over 700 seaweed species have been identified, of which 35% are endemic. Outside of the ocean many algae are found in freshwater both on the continent and on the subantarctic islands. Terrestrial algae, such as snow algae, have been found living in soil as far south as 86° 29'. Most are single-celled. In summer algal blooms can cause snow and ice to appear red, green, orange, or grey. These blooms can reach about 10 cells per mL. The dominant group of snow algae is chlamydomonas , a type of green algae.