Try to describe what are the shortcomings of the traditional plant taxonomy, and what new research methods have emerged at present?

The traditional classification, also known as the classical classification, is based on the external morphological characteristics of the plant body, supplemented by the knowledge of the geographical distribution of plants, which is a large amount of workload, cumbersome, and every little change in morphology brings certain difficulties in identification. At present, after summarizing the experience of the predecessors and synthesizing the results of recent scientific research, some of the following research methods are applied to help the old classical classification, i.e., the emergence of experimental taxonomy, and some achievements have been made in plant anatomy, plant cytology, sporology, genetics, biochemistry (including the characteristics of biomolecules, the method of determining serology and so on), ultrastructural taxonomy and so on. Currently numerical taxonomy uses quantitative methods to evaluate the similarity between organismal taxa and to categorize certain taxa into a higher class of taxonomic groups based on similarity values. Much work has been carried out in this area, which can more objectively reflect the similarity relationship between plants and the law of evolution. In short, modern taxonomy is not only the basis for other branches of botany, but its conclusions provide the basis for research in other branches.