CHAPTER VIII 

 THE CLASSIFICATION AND NAMING OF PLANTS 



That subject which deals with the arrangement of plants 

 into groups, based upon their structure and form, is desig- 

 nated Systematic Botany. From the earliest times, man has 

 attempted to classify the large and varied assemblage of 

 plants which he has found on the earth. There have been 

 many systems of classification, some "artificial," some 

 "natural." An artificial system of grouping plants may 

 use purely arbitrary bases; it may be convenient, but fail 

 to express the natural affinities of plants. For example, in 

 an artificial system, we might choose to put all those plants 

 with red flowers into one group, and those with blue flowers 

 into another class, and so on, thus basing our classification 

 on flower color. Or, we might put trees into one group, 

 shrubs into another, and herbs into still another, thus basing 

 the grouping on size and growth habit. Obviously, we 

 would throw together plants which have no natural relation- 

 ships, and in some cases, separate those which are naturally 

 allied. An artificial system would not take into account the 

 evolutionary tendencies in the plant world. It is agreed 

 that one system of classification is better than another if it 

 more accurately expresses the natural affinities and the 

 evolutionary tendencies of the organisms dealt with. 



In the early history of systematic botany, the systems of 



classification were largely artificial. As the knowledge of 



plants increased, one system supplanted another, and in 



most cases was an improvement over the old one. One of 



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