POLLINATION 



potent pollen is one of nature's many ways of preventing 

 self-pollination (Figs. 17 and 18). 



In planting an orchard or vineyard for home use it is 

 a good rule to plant several varieties of apples, several 

 of pears, and several of grapes, so that one variety may 

 supply pollen for the blossoms of the others. 



Pistils and stamens in different parts of the same plants. 

 We have called the pistils and the stamens the essential 

 parts of a flower because both are necessary to the forma- 

 tion of the seeds. When one flower bears both stamens 

 and pistil, it is called a perfect flower. But the pistil 

 and the stamens are not always found in the same flower. 

 In the corn plant, for example, the silks are the pistils, 

 while the stamens from which comes the pollen are found 

 in the tassel, another part of the same plant. Thus you 

 see that in corn the 

 staminate flowers are 

 borne on the top of the 

 plant and the pistillate 

 on the young ears of 

 corn growing on the 

 stalks of the same plant. 



On a squash, cucum- 

 ber (Fig. 19), or water- 

 melon the pistillate 

 blossom may be known by the little squash or melon which 

 shows below its yellow petals. These blossoms have pistils 

 but no stamens. In other parts of the same plants are 

 staminate blossoms, that have stamens, but no pistils and 

 no swollen part. Among other plants having stamens 



FIG. 19. CUCUMBER FLOWERS 

 On left, pistillate; on right, staminate. 



