HOW PLANTS GROW 347 



whorl of leaf-like parts just inside the calyx. The parts 

 of the corolla are called petals and they are usually 

 colored. 



These parts which are non-essential for reproduction 

 are the parts which give beauty to blossoms and which 

 make flowers so attractive for decorative purposes, and 

 also give them their high commercial value. Florists 

 aim to grow principally those plants which produce 

 beautiful sepals and petals; so from 

 the standpoint of the florist the non- 

 essential parts are very desirable. 



The essential parts consist of sta- 

 mens and pistil. The stamens are usu- 

 ally within the corolla, and each stamen 

 is composed of (i) a thread-like part 

 called the filament, (2) the anther, FLOWER 



which is often a knob-like body on 

 the outer end of the filament, and (3) the pollen, which 

 is usually a yellow, powdery substance that grows in 

 the anther. The pollen dust is composed of two-celled 

 bodies of various shapes, which may be plainly seen when 

 viewed through a microscope. The stamens are the male 

 parts of a flower. 



The pistil is in the center of a flower and is composed 

 of three parts. The base of it is called the ovary, which 

 is usually the largest part of the pistil and contains little 

 bodies called ovules; these can often be seen with the 

 unaided eye. On top of the ovary is a slender stem 

 called the style, and at the end of the style is the stigma. 

 The pistil is the female part of the flower. 



For fruit to be produced, the pollen from the anthers 

 must get on the stigma. It does this in several ways. 

 The anthers may burst when they are ripe and throw 



