Algae are an extremely diverse group of photosynthetic organisms that range from single-celled organisms to complex thalli. They are present in almost every habitat on this earth where moisture and sunlight are available. Free-living algae are mainly of two types: benthic algae live attached to living or non-living objects at the bottom of a water body, whereas planktic algae occur in free-floating conditions and often make the biggest contribution to the volume of algae growing in water bodies through the years. Extensive work on the taxonomy of algae of Uttar Pradesh has been carried out in all-natural types of freshwater ecosystems from a small puddle or pond to a big lake or a little stream to a tortuous river
