Abstract
The authors analyze Takhtajan's system of classification of the Angiosperms in relation to the principles of evolutionary and cladistic systematics. It is shown that Takhtajan belongs to the evolutionary school: he identifies the ancestors of some taxa, he accepts polytomous branching and he groups taxa on the basis of primitive as well as derived character states. Takhtajan's notion of weighted similarity does not appear to be based on objective criteria, when determining the weight and evolutionary status of characters.After a summary of the modifications brought out by Takhtajan in his 1980 version, the weak and strong points of evolutionary systems as a whole are emphasized. In these, the delimitation of taxa and their filiation are difficult to refute since they do not rely on precise criteria, which would ensure continuity and uniformity within a given system. However, these systems have some flexibility, which allows them to incorporate readily new information, a feature unfortunately missing in cladistic classifications. In fact, while it does have weaknesses from a theoretical point of view, the system of Takhtajan gives us an idea of flowering plants phylogeny that appears to be one of the most complete at the present time from both analytical and synthetic standpoints