PART FIRST. 



STRUCTUKAL BOTANY; OE, ORGANOGEAPHY. 



CHAPTER I. 



THE FLOWER. 



49. The flower is the immediate agent in the production ol 

 the seed with its embryo, and to this end its whole structure is 

 designed. Moreover, its superior beauty attracts earliest atten- 

 tion, and an intimate knowledge of its organism is the first re- 

 quisite in analysis and classification. 



50. The flower may consist of the following members the 

 floral envelopes and the essential floral organs. The floral envel- 

 opes consist of one or more circles or whorls of leaves surrounding 

 the essential organs. The outer of these whorls is called the 

 calyx and the other, if there be any, the corolla. The calyx 

 may, therefore, exist without the corolla ; but the corolla cannot 

 exist without the calyx. 



51. Calyx is a Greek word signifying a cup. It is applied 

 to the external envelope of the flower, consisting of a whorl of 

 leaves with their edges distinct or united, iisually green, but 

 sometimes highly colored. The leaves or pieces composing the 

 calyx are called sepals. 



52. Corolla is a Latin word signifying a little crown, applied 

 to the interior envelope of the flower. It consists of one or more 

 circles of leaves, either distinct or united by their edges, usually 

 of some other color than green, and of a more delicate texture 

 than the calyx. Its loaves are called petals. 



