Solving the mystery of the construction and elucidating the structural and functionality attributes of dichotomous key, a widely used tool for plant identification

The significance of correct identification of plants is acknowledged in many human endeavours such as health care, food production, sustainable housing, forest resources management and environmental protection. Plant identification is usually carried out by means of descriptions and keys, which are available in floras, manuals or other taxonomic publications, the most widely used tool being the dichotomous key. However, the construction and navigation of dichotomous keys are tedious. Thus identification is viewed by many practitioners as onerous task, which has led to declining interest in plant taxonomy. Therefore, the objective of this paper is to simplify the writing and application of the dichotomous key format, with the aim of making the practice of plant taxonomy more attractive, less laborious and dreaded for upcoming students of biology. A proposal on step-by-step, readily comprehensible procedure for making a dichotomous key from a conventional table of character comparison is presented. Some basic features of the key format (that is, couplets, leads, references, pointers, and endpoints), its variants (that is, indented and bracketed), and applicable enhancements, such as looping, nesting, and reticulations, use of polychotomous leads and tabula are illustrated and discussed.   Key words: Bracketed key, computerised key, diagnostic key, indented key, identity confirmation, nested key, reticulation, taxonomic key.