Marine life from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. Microorganisms constitute more than 90% of the marine biomass. A microorganism (or microbe) is a microscopic living organism, which may be single-celled or multicellular. Microorganisms are very diverse and include all bacteria, archaea and most protozoa. This group also contains some species of fungi, algae, and certain microscopic animals, such as rotifers. Many macroscopic animals and plants have microscopic juvenile stages. Some microbiologists also classify viruses (and viroids) as microorganisms, but others consider these as nonliving. In
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