Classification
Biological classification :- The art of identifying distinctions among organisms and placing them into groups that reflect their most significantant features and relationship is called biological classification.
The purpose of biological classification is to organise the vast number of known organisms into categories that could be named, remembered and studied.
According to "A.P. de Candolle", Classification is of two types-
(1) Empirical Classification
(2) Rational Classification
1. Empirical Classification :-
(i) In this type, the actual nature or character of plants is not considered.
(ii) Plants are classified on the basis of their alphabetical order.
(iii) In this way plants are classified into 26 groups.
(There are 26 alphabets in English- According to this classificalion, all plants having same initial alphabet are placed in one group. For example :- If the name of plants. starts from 'A', then it is placed in group". Similarly if it starts with 'B'. then it is placed in 'B group)"
2. Rational Classification :-
In this classification, plants are classified on the basis of their actual character of nature i.e. by viewing the character.
Type of rational classification
(i) Practical classification :- In this type of classification, plants are classified on the basis of their economical importance.
e.g. Oil yielding plants -> Coconut, Walnut, Soyabean
Fibre yielding plants ->Jute, Colton
Medicinal plants -> Rauwolfia, Cinchona, Eucalyptus
Note: In this classificalion, any one plant can be a member of more than one group.
eg- Turmeric : Multi uses plant, it gives both medicine and spices.
(ii) Artificial classification : In this type of Classification plants are classified on the basis of one or more characters. i.e. over all morphology is not considered.
for e.g.- Classification proposed by Linnaeus is Artificial.
Linnaeus classified plant kingdom on the basis stamen into 24 classes.
Note : Linnaeus classification is also called sexual classification.
Note : Linnaeus divided flowering plants into 23 classes starting with class monandria with single stamen (eg- Canna) and plants with twenty or more stamens attached with calyx were assigned to class Icosandria. He also included all non-flowering plants such as algae, fungi, mosses and ferns in a separate class called Cryptogamia.
(iii) Natural classification :- In this type, plants are classified on the basis of their complete morphological characters of stem, root, leaves, flowers etc.
Importance-
Natural classification is believed to be the best classification because it represents the natural similarities and dissimilarities of plants i.e. it represents the interrelationship among plants.
In this classification, the plants belonging to the same group shows many similarities, while in artificial classification the plant belonging to the same group shows only 1 or 2 similar characters. They have many dissimilarities.
Classification
Biological classification :- The art of identifying distinctions among organisms and placing them into groups that reflect their most significantant features and relationship is called biological classification.
The purpose of biological classification is to organise the vast number of known organisms into categories that could be named, remembered and studied.
According to "A.P. de Candolle", Classification is of two types-
(1) Empirical Classification
(2) Rational Classification
1. Empirical Classification :-
(i) In this type, the actual nature or character of plants is not considered.
(ii) Plants are classified on the basis of their alphabetical order.
(iii) In this way plants are classified into 26 groups.
(There are 26 alphabets in English- According to this classificalion, all plants having same initial alphabet are placed in one group. For example :- If the name of plants. starts from 'A', then it is placed in group". Similarly if it starts with 'B'. then it is placed in 'B group)"
2. Rational Classification :-
In this classification, plants are classified on the basis of their actual character of nature i.e. by viewing the character.
Type of rational classification
(i) Practical classification :- In this type of classification, plants are classified on the basis of their economical importance.
e.g. Oil yielding plants -> Coconut, Walnut, Soyabean
Fibre yielding plants ->Jute, Colton
Medicinal plants -> Rauwolfia, Cinchona, Eucalyptus
Note: In this classificalion, any one plant can be a member of more than one group.
eg- Turmeric : Multi uses plant, it gives both medicine and spices.
(ii) Artificial classification : In this type of Classification plants are classified on the basis of one or more characters. i.e. over all morphology is not considered.
for e.g.- Classification proposed by Linnaeus is Artificial.
Linnaeus classified plant kingdom on the basis stamen into 24 classes.
Note : Linnaeus classification is also called sexual classification.
Note : Linnaeus divided flowering plants into 23 classes starting with class monandria with single stamen (eg- Canna) and plants with twenty or more stamens attached with calyx were assigned to class Icosandria. He also included all non-flowering plants such as algae, fungi, mosses and ferns in a separate class called Cryptogamia.
(iii) Natural classification :- In this type, plants are classified on the basis of their complete morphological characters of stem, root, leaves, flowers etc.
Importance-
Natural classification is believed to be the best classification because it represents the natural similarities and dissimilarities of plants i.e. it represents the interrelationship among plants.
In this classification, the plants belonging to the same group shows many similarities, while in artificial classification the plant belonging to the same group shows only 1 or 2 similar characters. They have many dissimilarities.