Algae:

They are a type of plant that grows in water and flourishes in the presence of sunlight. They contain green substance chlorophyll, which permits them to utilize sunlight for their growth and conversion of carbon dioxide, water and other substances into organic carbon compounds. Hence, they flourish fast in sunlight. They are divided into three categories or groups - diatomaccae, chlorophyllceac and cyanophyccae. Each of the groups consists of many varieties.