28 . THE FLOWER. ‘ 
a. For example, the genus Trifoliwm includes the species T. repens, T. pratense, 
&c., agreeing in structure and aspect so obviously, that the most hasty observer 
would notice their relationship. Also in the genus Pinus, 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 affinities, grouped into genera. These divisions constitute 
the basis of all the systems of classification in use, whether by 
natural or artificial methods. 
%*y 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 still 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 his first requisites, on account of the indispensable use of the floral organs 
in classification. 
CHAPTER IV. 
THE FLOWER. 
gl. OF ITS PARTS, AND THEIR ARRANGEMENT. 
53. A FLOWER may consist of the following members :— 
1. The rLoraLt ENVELOPES, called, collectively, the PERIANTH, 
(ze9, around, «vFoc, a flower) ; 2. The stamens; 3. The PIsTILs; 
and, 4. The RECEPTACLE, Or TORUS. 
a. Of these, only the stamens and pistils are 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. 
6. If the stamens or the pistils, either or both, be wanting, the flower is said to 
be imperfect. An imperfect flower is either sterile, having stamens only, or fertile, 
haying pistils only, or neutral, having neither organs complete. * 
