The New Student's Reference Work/Taxonomy

From Wikisource
Jump to navigation Jump to search

Taxon′omy, that division of botany which deals with the classification of plants. It is one of the oldest of subjects, and not very long ago it was the only form of botanical instruction given in the schools. Specialists in this study are called taxonomists or systematists, but the plant-kingdom is so vast that no one can be a specialist in the taxonomy of all groups. Accordingly there are algologists, who classify algae; mycologists, who classify fungi; bryologists, who classify mosses; pteridologists, who classify ferns. Ordinarily, when a man is called a systematist or a taxonomist, without any qualification, he is a specialist in the classification of seed-plants. The early attempts to classify plants were purely artificial, that is, there was no effort to indicate their real relationships. For example, one of the earliest groupings of seed-plants was into herbs, shrubs and trees. This brought together many wholly unrelated plants and kept apart many which are closely related, as unrelated words are brought together in a dictionary by the accident of their first letter. The artificial system was most highly developed by Linnæus, who invented an elaborate scheme on the basis of the number of stamens and pistils in the flower. This scheme was used until quite recently, but it has now been entirely replaced by natural systems. These systems attempt to group plants together which are really related, a family in botany meaning about what the term means among human beings, if one substitutes species for individuals. A natural system of classification can only become perfect when the complete development and structure of every plant are known. Hence such systems are being constantly revised as knowledge increases.