Taxonomists have tried various methods to classify the plants and other organisms since historical time. There are three major systems:
1. Artificial system of classification was initiated by Theophrastus (370 to 285 BC) and gained maximum attention after Linnaeus proposed his classification. He grouped the plants into various categories based on habit, colour, and floral characters like number and nature of stamens and carpels. Thus, the vegetative and reproductive characters were dealt with equal weightage. This separated, sometimes, the related species afar.
2. Natural system of classification was proposed for the first time by Bentham and Hooker (1833 to 1862). This system was based on the detailed study of the flowers of the plants. The book in which these two scientists have proposed their classification system is Genera Plantarum.
3. Phylogenetic system of classification was proposed as post-Darwinian systems after Darwin proposed theories of evolution. These systems are based on evolutionary relationship and genetic resemblances. Some examples of this system could be Hutchinson's system, Bessey's system of classification. Engler and Prantl were the first to propose a phylogentic system.