THE CLASSIFICATION OF PLANTS. 



215 



others, combine to make up the Crowfoot familj*. In deter- 

 mining tlie classification of plants most points of structure 

 are important, but the characteristics of the ilower and fruit 

 outrank others because they are more constant, since they 

 vary less rapidly than the characteristics of roots, stems, 

 and leaves do under changed conditions of soil, climate, or 

 other surrounding circumstances. Mere size or habit of 

 growth has nothing to do with the matter, so that the 

 botanist finds no difB.culty in recognizing the strawberry 

 plant and the apple tree as members of the same family. 



This family affords excellent illustrations of the meaning 

 of the terms genus, species, and so on. Put in a tabular form, 

 some of the sub-divisions of the Rose family are as follows : 



« 





Plum genus 



Rose genus 



Pear genus 



Peacli species (many varieties). 



Garden plum species (many varieties). 



Wild black cherry species. 



Garden red cherry species (many varieties). 



Dwarf wild' rose 



species. 

 Sweet-brier species. 



^ , . . ( Tea variety. 



India rose species i _, . ^ 



( Pompon variety, etc. 



Damask rose species. 

 Pear species 



Seckel variety. 

 Bartlett variety. 

 Sheldon variety, etc. 



Apple species 



Baldwin variety. 

 Greening variety. 

 BellSower variety. 

 Northern Spy variety, 

 etc. 



