EXERCISE 46 

 THE PARTS OF A FLOWER 



Materials. Any fairly large flower that can be secured in the 

 autumn excepting the composites, such as goldenrod, aster, chrysan- 

 themum, and dandelion. Flowers of house plants, if not " double," 

 may be used. 



Directions for work. By the aid of the textbook identify 

 sepals, petals, stamens, pistil, receptacle. Identify also the parts 

 of the pistil ovary, style, stigma. Beginning at the outside of 

 the flower, pick off each of the parts of the flower, noting where 

 it is attached, its relations to the other parts, and its form and 

 color. When you have satisfied yourself that you know the 

 relation of the different parts to each other, make a floral 

 diagram showing an ideal vertical section through the flower 

 and another showing the plan of the flower. These are com- 

 monly known as vertical diagrams and horizontal diagrams. In 

 making the horizontal diagrams draw the circle upon which 

 the diagram is built with a compass. Use the same shapes 

 and shading to represent petals, sepals, etc. as are used in the 

 figures. Be careful to make the diagrams symmetrical. 



After having completed the study of the first flower, examine 

 several others, making floral diagrams. At least five should be 

 studied. 



Compare the series of completed horizontal diagrams. Is the 

 number of sepals the same in all the flowers studied? What 

 are the most common numbers ? In the flower first studied are 

 the petals of the same number as the sepals, or a multiple of 

 the same number, or is the number of petals wholly unrelated 

 to the number of sepals ? What is the number of stamens, and 

 how does it compare with the number of sepals and petals ? 

 Can you detect any numerical plan in the flower? 



Study each of the horizontal diagrams in turn with reference 

 to the numerical plan. 



Compare the vertical diagrams with reference to the attach- 

 ment of the several organs of the flower. In the first flower 

 studied are the sepals inserted upon the receptacle ? Are the 



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