EXERCISE 116 



The flower is the seed-producing part of a plant, although the part that we usually notice is not the 

 one that makes seeds. 



Problem. What are the organs of a flower, and how do they make seeds ? 



What to use. A complete, 1 regular, 2 and perfect 3 flower, such as the tulip or wild rose; a 

 magnifying glass. 



What to do. Examine the parts of the flower and their arrangement. 



NOTE I . The parts of the flower are arranged in circles, or rings, and are all attached to an enlargement of the end of 

 the stalk, called the receptacle. 



NOTE 2. The outer circle is called the calyx; and its parts, which may be quite distinct or more or less fused 

 together, are called sepals. 



NOTE 3. The second circle (from the outside) is called the corolla ; and its parts, which may be distinct or united, 

 are petals. 



NOTE 4. The calyx and corolla together constitute the floral envelope and are not essential to the making of seeds. 

 In many kinds of plants the flower has no envelope. 



NOTE 5. The central organ is the pistil and may consist of one or several carpels (which can usually be recognized 

 by ridges running lengthwise). The main parts of the pistil are the ovary, or seed-bearing chamber, usually the thickest 

 part and at the base ; the stigma, or tip ; and the part connecting stigma with ovary, or the style. 



NOTE 6. The stalklike or threadlike structures with little knobs, surrounding the pistil, are the stamens. The stalk 

 is called the filament, and the pollen-case at the top is the anther. 



Record. Make diagrams to illustrate the structure of the whole flower and the arrangement of the 

 parts ; label every structure named in the notes. 



Make a cross section of the ovary, and draw, showing the separate carpels and the area carrying the 

 ovules, which are to become the seeds. 



NOTE 7. The surface to which ovules are attached is called the placenta. 



1 A complete flower is one that has a floral envelope as well as the seed-making organs. 



2 A regular flower is one in which the organs of each circle are all alike as to form. 

 8 A perfect flower is one that has both stamens and pistils. 



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