The term key refers to a set of alternate characters in such a manner that helps in the identification of plants and animals by selecting and eliminating the characters according to their presence or absence in the organism under study. There is a species key for the identification of species in a genus, a genus key for the indentification of genera in a family and soon. These keys are based on the contrasting characters generally in a pair called couplet. It represents the choice made between two opposite options. This results in acceptance of only one and rejection of the other. Each element in a key is called a lead, keys are generally analytical in nature. Flora, manuals, monographs and catalogues are some other means of recording descriptions. They also help in correct identification of organisms. Flora contains the actual account of habitat and distribution of plants of a given area. These provide the index to the plant species found in a particular area. Manuals are useful in providing information for identification of names of species found in an area : Monographs contain information on any one taxon.