The morphological characters can even be studied in a dry preserved plant specimen in a herbarium or the fossil taxa. The similarities and/or differences in morphology can provide a good understanding of the level of variation in an organism as well as its evolutionary relationship. Apart from macromorphology, micromorphological characters such as stomata type, trichome variations, epidermal surface, venation pattern, etc. have also been used in taxonomic studies. Reproductive characters that are most commonly used in characterization of taxonomic groups include inflorescence type, flower symmetry, ovary position, arrangement of androecium and gynoecium, fruit shape, and seed surface ornamentation. Reproductive characters have always been preferred more than the vegetative characters. Most of the vegetative characters associated with roots, stem or leaf are easily observable and can readily help to identify a particular taxon. Leaves are the main photosynthetic organs of a plant that develop from the nodes. Trichomes are cellular appendages that develop from the epidermal cells.