Synopsis The publication "The Structure and Reproduction of the Algae" volume I by F.E. Fritsch is a valuable book in phycology. Since then green algae (Chlorophyta) research has advanced and diversified that during the past few decades have witnessed an unprecedential new findings which have accrued through the use of modern methodology and newer techniques. The knowledge thus gained is scattered in various journals, usually inaccessible to many students and research scholars. Our aim is to summarize the current knowledge that will aid students, researchers and teachers interested in this fascinating area of phycology. The chlorophyta are primarily freshwater but about 10% are marine. The order siphonales is predominantly marine whereas ulotrichales, oedogoniales are freshwater with cosmopolitan distribution. The variety of taxa in the chlorophyta are diverse and varied which necessitated us to select only a few examples which are easily available.