COMPARING AND CLASSIFYING PLANTS. 75 



with those of the other in number of parts and in the 

 position of parts. They differ only in color and outline. 

 The stamens of one are like those of the other in being 

 numerous and hypogynous. The pistils agree in structure, 

 but differ in the number of carpels. If you compare the 

 leaves, stems, inflorescence, etc., you also get a list of their 

 resemblances and differences. This is comparing plants 

 by the groups of characters they present. 



These resemblances of character among plants are called 

 their affinities. 



The degree of affinity between plants depends upon 

 two circumstances : First, upon the kind of characters in 

 which they agree ; and, second, upon the number of char- 

 acters in which they agree. 



The characters of plants differ in importance. Color, 

 size, and odor, being usually more variable than position 

 and number, they are said to be less important than these. 

 The characters of the leaf, for the same reason, are not 

 usually as important as those of the flower. In the be- 

 ginning of study, you may assume that those plants have 

 the strongest affinities that resemble each other most in 

 the characters recorded in the cohesion and adhesion col- 

 umns of the schedule. 



To make this plainer, compare the poppy and buttercup, 

 as, before, you compared the columbine and buttercup. 



BUTTERCUP. 



Calyx. Sepals, 5, polysepalous, 

 inferior. 



Corolla. Petals, 5, polypeta- 

 lous, hypogynous. 



Stamens. Polyandrous, hypo- 

 gynous. 



Pistil. Carpels, many, apo- 

 carpous, superior. 



Leaves. Net-veined, divided. 



Juice. Watery. 



POPPY. 



Calyx. Sepals, 2, polysepalous, 

 inferior. 



Corolla. Petals, 4, polypeta- 

 lous, hypogynous. 



Stamens. Polyandrous, hypo- 

 gynous. 



Pistil. Carpels, many, syn- 

 carpous, superior. 



Leaves. Net-veined, divided. 



Juice. Milky. 



