A. ARTIFICIAL
SYSTEM OF CLASSIFICATION
In
this system of classification, the plants are classified based upon a few
convenient characters for the purpose of classification. For example – the
grouping of plants into herbs, shrubs and trees or Lineaus system of
classification was based on the characters of stamens. The ancient systems of
classification were strictly artificial. Theopharastus
(370-285 BC) also called as the “Father
of Botany” classified plants on the basis of their habit into herbs, shrubs
and shrubs.
B. NATURAL SYSTEM OF CLASSIFICATION
In this system of
classification, all the important characters of plants are being considered and
the plants are classified according to their related affinities. The natural
system of classification was proposed by Bentham and Hooker and is the best
known and most acceptable system of classification.
C. PHYLOGENETIC
SYSTEM OF CLASSIFICATION
In this system of
classification, the plants are classified according to their evolutionary and
genetic affinities. As it is difficult to classify plants perfectly on the
basis of evolutionary tendencies because of the imperfection of fossil records,
and hence, at present plants are classified partly according to natural and
partly according to phylogenetic basis. Engler
and Prantl’s system, Hutchinson’s system, Takhthajan’s system, etc. are
classified according to phylogenetic system of classification.
D. PHENETIC
SYSTEM OF CLASSIFICATION
In this system of
classification, maximum numbers of generalizations are made from general
classifications and totality of characters
of living plants are considered and classification is based on the living
phenotypes with all possible methods. Natural system of classification is
considered to be a phonetic type of classification.
E. PHYLETIC
SYSTEM OF CLASSIFICATION
In this system of
classification, plants are classified based on the relationship to a particular
line of descent. There are two components of phyletic relationship – (a) Cladistic and (b) Patristic. Cladistics and Patristics are the terms used to express
the affinity in phylogenetic context.
“Cladistic” is used to denote closeness of relationship in terms of
phyletic lines and refers to the actual pathways by which a given similarity
has been attained. “Patristic” is
used to denote the similarity between two plants due to known common ancestry.
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