PARTS OF THE FLOWER 11 



Functionally, the flower may be defined as the organ which has 



to do with seed production. Flowers which have been so modi- 



fied through cultivation that they no longer produce seed are not 



true flowers. However, the true function of the flower is often 



not the important feature to the plant grower. Many flowers 



are cultivated entirely for their aesthetic charm. In case of 



fruit trees, Tomatoes, and many other plants, the structure 



developing from the flower and 



known as the fruit is more 



important to the plant grower 



than the seed. However, when 



plants are grown for seed or 



fruit, the amount of seed or fruit 



harvested depends very much 



upon the number of flowers pro- 



duced. For example, the gar- 



dener does not expect to gather 



many Beans or Peas if the Fio.3. Apetalous flower of Buck- 



vines produce only a few flowers. wheat " f M 



T . r, receptacle. Much enlarged. After 



Likewise, good crops of Clover Marchand. 



and Alfalfa seed depend upon a 



good crop of flowers; and not much fruit is expected when the 

 flowers in the orchard are few. It is in connection with the 

 function of reproduction, that flowers have developed the various 

 colors, forms, and odors which assist in bringing about fertiliza- 

 tion. Fertilization is the all important process in sexual produc- 

 tion and the organization of flowers centers about this process. 

 Unless fertilization occurs flowers very rarely develop any seeds. 



Despite the multitudinous forms and colors which flowers 

 present, there is much unity and simplicity in structure, all parts 

 being organized to assist in performing the function of seed 

 production. 



Parts of the Flower. The parts of a flower are of two general 

 kinds; those which are directly concerned in the production of 

 seed; and those which act as protective and attractive organs. 

 The former are known as the essential organs, and consist of 

 stamens and pistils. The latter are known as floral envelopes 

 or perianth, and usually consist of two sets of organs, one called 

 calyx and the other, corolla. In Figure 2, the calyx is the lowest 

 whorl and consists of green leaf-like portions called sepals. The 



