184 



FLOWERS 



parents of the baby plant or embryo are the stamens and pistils of 



the plants which produced them. 



The sign $ stands for the male plant 

 or animal and the sign ? indicates the 

 female. In the accompanying illustra- 

 tions are seen male and female flowers 

 of several common plants. 



When a flower possesses both the 

 essential organs, it is said to be perfect. 

 If only one kind of sex organs is present, 

 the flower is said to be imperfect. If both 

 kinds of flowers (staminate and pistillate) 

 are found on one and the same plant, it 

 is said to be monoecious, but when they 

 occur on separate plants, they are said to 

 be dioecious. 



To which class do ailanthus, pine, 

 corn, sheep-sorrel (rumex), ragweed, castor 

 bean, willow, hazel, alder, chestnut, hick- 

 ory, belong? Examine several flowers of 

 Jack-in-the-pulpit and find three varieties: 

 (1) all staminate, (2) all pistillate, (3) both 

 sorts (polygamous). Squash flowers also 

 are polygamous. 



FIG. 78. A, sedge; B, oak; 

 C, sugar maple. 



164. SEX ORGANS OF FLOWERS 

 Object. To learn what is meant by imperfect flowers. 



Apparatus. Sterile and fertile flowers of any direcious plant, 

 for example, a cone-bearing plant (pine or spruce), and a magnifier. 



Method. ( a ) The male flower. Examine the whole 

 flower (cone). Cut it open from end to end and note the 

 attachment of the scales and the position of the stamens. 



Remove one stamen. Note its form and the number of 

 its pollen sacs. Where do these pollen sacs grow, on the 

 upper or under side of the stamen? Can you find where 



