Natural system classification of Plant Kingdom: The natural system of classification is a type of classification in which properties such as morphology, cytology(cell structure), phytochemistry(chemicals found in plants), embryology, and anatomy are applied to find similarities and affinities among organisms. These characteristics help in bringing out the maximum number of similarities as well as dissimilarities. Homology is also considered among diverse organisms. It is the relationship of comparable structures having been derived from a common form. For e.g. the forearm of different land vertebrates has the same pentadactyl (five fingers or toes)constitution but different externally. It has evolved to meet an organism’s requirement like grasping in human beings, running in horses, swimming in whales and flight in birds or bats.

• According to a natural classification system, all members of a particular group would have shared a common ancestor
• This means that natural classification schemes can be used to predict characteristics shared by species within a group
• A disadvantage of such schemes is that they are highly mutable and tend to change as new information is discovered.

Merits and Demerits of Natural system classification of Plant Kingdom

Merits of Bentham’s and Hooker’s systems are as follows:

(i) It is practically important, as most of the herbaria of the world are based on this system of classification.
(ii) They placed Ranales (most primitive) in the beginning of classification that is phylogenetically true.
(iii) They placed monocots after dicots which is similar to phylogenetic systems.

Demerits of Bentham’s and Hooker’s classification systems are as follows:

(i) They did not use phylogenetic trends in their classification.
(ii) Gymnosperms are placed between dicots and monocots which is not acceptable.
3) Monochlamydeae is placed after gamopetalae which does not seem to be natural.
4) Some of the associated orders are geographically isolated.
5) Groups are not arranged in a consistent manner.

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By Team Learning Mantras