PART FIRST. 

 STRUCTURAL BOTANY; OR, ORGANOGRAPHY. 



CHAPTER I. 



THE FLOWER. 



49. The flower is the immediate agent in the pro- 

 duction of the seed with its embryo, and to this end 

 its whole structure is designed. Moreover, its superior 

 beauty attracts earliest attention, and an intimate 

 knowledge of its organs is the first requisite in analy- 

 sis and classification. 



50. The flower may consist of the following mem- 

 bers the floral envelopes and the essential floral or- 

 gans. The floral envelopes 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 can not exist without the calyx. 



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

 applied to the external envelope of the flower, consist- 

 ing of a whorl of leaves with their edges distinct or 

 united, usually green, but sometimes highly colored. 

 The leaves or pieces composing the calyx are called 

 sepals. 



