The study of the principles and practices of classification. The term taxonomy is strictly applied to the study and description of variation in the natural world and the subsequent compilation of classifications. However, it is often used more loosely and includes the part of biological science referred to as *systematics
. Taxonomy is a vast subject and various sections can be recognized within the discipline. In dealing with the flora of an area several phases can be recognized. The first phase is mainly concerned with identification and is sometimes referred to as exploratory or pioneer. Study of many tropical areas is still in this stage. Once material is better known and taxonomists have a good understanding of local and regional variation of the species it moves into the consolidation phase (the flora of Europe comes into this category). These two phases are jointly described by some as 'alpha' taxonomy. Once cytological or *biosystematic
data are available these can be added to existing data. Taxonomy in which all available evidence is considered is described as the encyclopaedic phase or 'omega' taxonomy. Some authors make further distinctions between classical (mainly intuitive) and experimental approaches, the latter including biosystematic, chemosystematic, and numerical procedures.