CH. IX] THE CLASSIFICATION OF PLANTS 393 



Oak, and Red Maple, Oak and Maple being generic names in 

 English, as are Quercus and Acer in Latin. Families are 

 named usually from some prominent genus, commonly with 

 the termination -acecB] thus Rosacece is the Rose Family. 

 Orders are named usually from some prominent Family, 

 commonly with the termination -ales ; thus Rosales is 

 'the order which includes the Rose Family along with a good 

 many others. The Classes are named usually from some 

 prominent group, commonly with the termination -inece; 

 thus FilicinecB is the Class containing the Ferns. The Divi- 

 sions are named with the termination -phyta. 



If classification is to plants the same as genealogy to men, 

 we should be able to construct for plant relationships a 

 table or tree of descent. This can indeed be done in a general 

 way, though with much uncertainty as to details because 

 of our scant knowledge at many places. Such a tree, con- 

 structed in accordance with the data contained in the four 

 following chapters, is presented herewith (Fig. 275) . Details 

 of classification are expressed in form convenient for use in 

 books called Manuals (page 3), while the plants of a country 

 collectively, considered from this point of view, are called 

 its Flora, a word often extended to books descriptive 

 thereof. 



Plants are related to one another not by single characters 

 but by aggregates of many, more or less linked together and 

 various in prominence. Usually, however, it happens that 

 some one of the correlated features stands out so prominently 

 that we can use it conveniently as an index to the aggrega- 

 tion ; and this is the meaning of distinctions between groups 

 based apparently on single features. Thus the classification 

 of the Algae into Green, Brown, and Red does not mean that 

 Algae are classified by color; but it happens that color in 

 those plants is usually a safe, and certainly a convenient, 

 index to the structural features which separate them. The 

 method, however, has its dangers and drawbacks, because 

 sometimes all of the other characters may be present without 



