2i66 



A TEXTBOOK OF THEORETICAL BOTANY 



II. Monocotyledones — contd. 



6. Potamogetonales 



7. Najadales 



8. Commelinales 



9. Xyridales 



10. Eriocaulales 



11. Bromeliales 



12. Zingiberales 

 [3. CoroUiferae 



I. 



2. 



3- 

 4- 

 5- 



Liliales 



Alstroemeriales 



Arales 



Typhales 



Amarvllidales 



THE METHOD OF CLASSIFICATION ADOPTED IN THE PRESENT 



WORK 



In the light of what has been said in this chapter it will be clear that the 

 authors have not had an enviable task in formulating a scheme of classifica- 

 tion applicable to a book of this kind. They have from time to time ventured 

 to express their own views on classification of certain groups but to justify 

 these views would involve excursions into phylogeny which they feel 

 should not be intruded into a work dealing with facts rather than with ideas. 



The method of classification adopted in this book is, however, stated at 

 appropriate points in this and the preceding volume. Since at this stage 

 the purely systematic portion of the subject has been completed it seems 

 appropriate to close this chapter and Volume II with a synopsis of the 

 classification of plants as followed in this work. For the sake of clarity it 

 includes certain groups which are not considered in detail in the preceding 

 chapters but omits many of the less common or less well-known groups. 



In studying such a scheme the student must fortify himself against 

 regarding it as representing more than a working plan. It does represent 

 a view of the relationships of plants but nothing more and in the years to 

 come it will probably be as out of date as some of the schemes we have 

 already quoted in this chapter. But as knowledge grows so the picture 

 becomes clearer; finer details have still to be sketched in, but the general 

 outline of the picture is there and its form can be appreciated. It must be 

 remembered, however, that just as a picture must, in two dimensions, 

 portray a scene which exists in three, so a scheme of classification on paper 

 can only imperfectly illustrate the complexly branched system we believe to 

 represent the course of Evolution. It is the reticulate concept of a Natural 

 or Phylogenetic System of Plant Classification which we must appreciate 

 if we are to understand Nature as we believe she really works. 



