28 THE FLOWER. 



a. For example, the genus Trifolivm includes the species T. repens, T. prateru€f 

 &c., agreeing in structure and aspect so ob\'iously, that the most hasty observer 

 would notice their relationship. Also in the genus Finns, no one would hesitate 

 to include the white pine and the pitch pine (P. strobus and P. rigida), any more 

 than he would fail to observe their differences. 



b. Thus, the whole vegetable kingdom is, by the most obvious 

 characters, distributed into species, and the species, by truly nat- 

 ural afiinities, grouped into genera. These divisions constitute 

 the basis of all the systems of classification in use, whether by 

 natural or artificial methods. 



^*^ To the admirer of nature, flowers are among the first subjects of atten- 

 tion, as mere objects of taste. They are conspicuous for their superior beauty, 

 even in the vegetable kingdom, where all is beautiful. Yet, as objects of science, 

 they merit a stiU higher regard, whether we consider the Creative skill displayed 

 in their construction, or their important agency in the reproduction of the plant 

 But, to the practical botanist, an intimate knowledge of their organic structure is 

 one of Ms Jirst requisites, on account of the indispensable use of the floral organs 

 in classification. 



CHAPTER IV. 



THE FLOWEB. 



§1. OF ITS PARTS, AND THEIR ARRANGEMENT. 



53. A FLOWER may consist of the following members : — 

 1. The FLORAL ENVELOPES, Called, collectively, the perianth, 

 (nsQi, around, avd-og, a flower) ; 2. The stamens ; 3. The pistils ; 

 and, 4. The receptacle, or torus. 



a. Of these, only the stamens and pistils ai-e regarded in science as essential 

 parts. These, together with the receptacle, are said to constitute a perfect flower, 

 even when one or all other parts are wanting ; because these two organs alone 

 are sufficient for the perfection of the seed. In a popular sense, however, a per- 

 fect flower must possess all the organs above mentioned. 



b. If the stamens or the pistils, either or both, be wanting, the flower is said to 

 be imperfect. An impeifect flower is either steriU, having stamens only, or fertile, 

 having pistils only, or nciUral. having neither organs complete. 



