Cytology section undertakes the studies related to the morphology and physiology of plant cells. It involves the collection of fresh plant samples from different areas of Nepal, preparation of permanent slides and their subsequent observation under compound microscope thereby characterizing each of the species studied through their cytological features. Researches on cyto-taxonomy of morphologically similar plants may reveal their phylogenetic positions and thus help to ascertain their taxonomic status. Cytological information such as number, shape, size and behaviour of chromosomes and genome analysis helps to establish the evolutionary relationship among the species. Cyto-taxonomical attributes including chromosome number, morphology, ploidy level, ploidy type and chromosomal aberrations provide valuable data for classification of plants.