PABTIGULAB TYPES OF FLOWJSBS 



207 



Fia. 201. 

 The sweet pea flower. 



tion, by way of illustration. We shall be still fur- 

 ther impressed with the fact that, while there are 

 certain fundamental resemblances 

 in flowers, there are endless dif- 

 ferences in details. 



237. An outline of the sweet 

 pea flower is shown in Fig. 

 201. The calyx plainly has five 

 parts, but the corolla evidently 

 has but four. The prominent 

 part is the standard or banner 

 (also called the vexillum), shown 

 at s. In front of it are two 

 wings, WW. In the very front of the flower is a 

 part which, because of its shape, is known as the 

 keel, h. This pea-like type of corolla (which the 



pupil will recall in the 

 beans, clover, locusts, 

 and the like) has been 

 likened to a butterfly in 

 shape ; and such flow- 

 ers are therefore said to 

 be papilionaceous (Latin 

 "papilio," a butterfly). 



238. Searching, now, 

 for the essential organs, 

 we find a structure like Fig. 202, There are ten 

 stamens, nine of them united by their filaments 



Fig. 202. 



Essential organs of sweet pea. 

 Calyx at v, but corolla remoyed. 



