Q. Phylogenetic systems of classification?

As already pointed out 'earlier that in Phylogenetic system, the plants are classified according to their evolutionary relationships. It is very difficult to claim that a phylogenetic system is perfect on the basis of evolutionary affinities due to incomplete fossils records and in such a situation the plants are classified on the basis of available data. The systems of classification by Engler and Prantl (1887-1915), Hutchinson (1926, 1934, 1969 and 1973) and by Takhtajan (1954, 1964, 1973, 1980) are Phylogenetic systems. We shall discuss these systems one by one in details.