What is taxonomy ? Give a brief account of different types of plant classification.

Explanation

Plant taxonomy deals with characterization, Identification nomenclature and classification of plants. Several classifications were proposed by different taxonomists based on various criteria. All these classifications can be grouped into 3 types.
1. Artificial systems, 2. Natural systems, 3. Phylogenetic systems.
1. Artificial systems : These systems are based on one or few easily comparable characters like morphology, nutritional habits etc.
e.g. : (A) Classification of plants into herbs, shrubs, trees etc., on the basis of form by Theophrastus in his book "Historia Plantarum".
(B) Sexual system of Linnaeus, in which he classify the plants on the basis of morphological nature of stamens and carpels.
2. Natural systems : These are the systems in which plants are grouped on the basis of their natural reltionships taking into consideration all possible morphological characters. They believed that all species are specially created by God and they do not undergo any change.
E.g. : Classification of Bentham and Hooker.
3. Phylogenetic systems : The classification of post-Darwinian period considered evolutionary trends in plants and so they are consider as Phylogenetic systems. In a phylogenetic system, primitive and advanced characters an recognised. While considering the status of a taxon, a comprehensive picture of all the characters is taken into account. The system proposed by Engler and Prantl in their book, "Die Naturlichen Planzenfamilien" (1887-1893) and by J.Hutchinson (1954) in his book, "Families of flowering plants" are examples. The latest phylogenetic system is APG (Angiospermic Phyogenetic Group) system.