FORM AND STRUCTURE 



THE INDIVIDUAL FLOWER. 



A complete flower consists of four sets of organs which 

 botanists regard as modified leaves. These are Calyx, Co- 

 rolla, Androecium the Stamens, and Gynoecium the pistils. 

 They are borne on a short axis called the receptacle. 



(Fig. 35.) 



The Calyx is the outer set. This is usually green though 

 sometimes it is colored. It may consist of a number of 



separate parts called 

 Sepals ; these may be 

 more or less united. 



The Corolla is the 

 second set. This is 

 usually colored. It may 

 consist of a number of 

 separate parts called 

 petals; these may be 

 more or less united. 



The calyx and corolla 

 are called the floral 

 envelopes because they 

 surround and protect 

 the stamens and pistils, 

 which are the essential 

 organs of the flower. 

 They are called essen- 

 tial organs because to- 

 gether they produce 

 the seed. 



The Stamens consti- 

 tute the third set. A 

 filament and the anther. 

 The Anther is the essen- 



FiG. 35. 



Cherry Blossom, Showing Calyx (bud), 

 Corolla, Stamens, and Pistil. 



stamen consists of two parts, the 



The Filament is the anther stem. 



tial part and contains the Pollen which it discharges when 



mature. When the filament is wanting the anther is said to 



be sessile. 



The Pistils are at the centre of the flower. It is not often 



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