Ice algae terrestrial ice algae occur in freshwater systems, the species composition differs greatly from that of sea ice algae. These communities are significant in that they often change the color of glaciers and ice sheets, impacting the reflectivity of the ice itself. Microbial life in sea ice is extremely diverse, and includes abundant algae, bacteria and protozoa. Algae in particular dominate the sympagic environment, with estimates of more than 1000 unicellular eukaryotes found to associate with sea ice in the Arctic. Species composition and diversity vary based on location, ice type, and irradiance. In general, pennate diatoms such as "Nitschia frigida"
Tamil Nadu cultivated plants and 230 red-listed species. The Gymnosperm diversity of the country is 64 species of which Tamil Nadu has four indigenous species and about 60 introduced species. The Pteridophytes diversity of India includes 1022 species of which Tamil Nadu has about 184 species. Vast numbers of bryophytes, lichen, fungi, algae and bacteria are among the wild plant diversity of Tamil Nadu. Common plant species include the state tree: palmyra palm, eucalyptus, rubber, cinchona, clumping bamboos ("Bambusa arundinacea"), common teak, "Anogeissus latifolia", Indian laurel, grewia, and blooming trees like Indian labumusum, ardisia, and solanaceae. Rare and unique plant life includes