ABSTRACT

The term phenetic was introduced by A. J. Cain and G. A. Harrison. They defined phenetics as “overall similarity based on all available characters without any weighting”. The principles of Phenetics or Numerical Taxonomy were given by P. H. A. Sneath and R. R. Sokal in 1973. However, characters that are phenotypically overlapping and show variations even within an taxonomic unit are difficult to code like color intensity or length of petiole. The problem in coding arises when characters have phenotypic overlapping or some related taxa are not represented by authentic specimens. Two-state characters are the most commonly used in plant taxonomic studies. A more comprehensive work on development of plant biometrics is needed to have a reliable system for identification of plants using biometrics and it can be done by developing a robust database and adding reference images of new species to that database.