The following points highlight the thirty-six important Swingle’s principles for plant classification. Swingle’s Principle # 1. Plant relationships are up and down genetic lines and these must constitute the framework of phylogenetic taxonomy. Swingle’s Principle # 2. Some evolutionary processes are progressive while others are regressive. Swingle’s Principle # 3. Evolution does not necessarily involve all organs of the plant [...]
Taxonomy is fundamentally a descriptive and highly documented science. Its literature is voluminous and constitutes so vital a part of its structure that, irrespective of whether the problem is one of identification of an unknown plant, solution of a nomenclatural puzzle, or a monographic or floristic study, acquaintanceship must be made with the more important publications of the subject. Every [...]
The following points highlight the fifteen important Thorne’s principles (1958) of plant classification. Thorne’s Principle # 1. Existing species have descended with change from pre-existing species and are therefore, the products of evolutionary forces. Thorne’s Principle # 2. Ancestral conditions and trends of specialisation are often recognisable in the organs, tissues and cells of living and fossil angiosperms. Thorne’s Principle [...]