SECTION II. THE PARTS OF THE FLOWER. 

 PLANT FAMILIES 



THE chief effort of the plant is to produce seed. A 

 flower must be formed before the seed can be produced. 

 Its beautiful colors, its nectar, and its delicious perfume 

 are means to attract insects whose help it may require in 

 making seed. 



Mustard flower. As our first example, we may inquire 

 what are the parts of a mustard flower (Fig. 4). In the 



FIG. 4. FLOWER OF FIG. 5. DETAILS OF PART 



MUSTARD OF MUSTARD FLOWER 



center of this flower is a column, at the top of which is a 

 rounded knob (o, Fig. 5). The whole central column is 

 called the pistil. Its important parts are the ovule case, 

 near the base, in which the seeds develop ; and the stigma, 

 or knob at the top. In some plants the stigma is divided 

 into several parts. The surface of a full-grown stigma is 

 sticky or rough, so that pollen, which is the yellow dust 

 of the flower, may stick to it. The ovule case, or ovary, 



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