Division chlorophyta
Organisms of highly variable organisation: unicellular, filamentous, siphonous (without walls) and parenchymatous. They have chlorophylls a and b, which give them their green colour, and starch as a storage product. Their cell walls are cellulose, as with land plants. They are very common in freshwater, whereas in the marine medium they are represented by just a few genera. They are highly abundant in warm seas. Some species develop in eutrophic places; therefore they can be indicators of pollution.
