In classifying a plant or an animal, it is necessary to label it by some name. Normally a plant or an animal is known by its local or popular name which differs from place to place. Therefore, Carolus Linnaeus, a Swedish naturalist, introduced a system of binomial nomenclature. According to this system, every plant and animal is given a double name first its generic (GENUS) and second its specific (SPECIES). Its application by Linnaeus in 1753 to plants and in 1758 to animals is now followed universally.