FLOWERS: POLLENATION AND FERTILIZATION 111 



may be almost sure that some special adaptation for insect visitors 

 stands behind the curious shape. 



Adaptations for Wind Pollenation. Flowers which depend on 

 wind for their pollenation are very differently adapted. They 

 produce enormous quantities of pollen, but they have no nectar 

 or odor. Their pistil is usually large to catch the flying pollen, 

 and they secure access to the wind by having very small corollas 

 and by producing their flowers above the leaves of the plant. 



FIG. 34. Salvia-flower. 



A, showing position of pistil and stamens; 



B, anthers of stamens in normal position; 



C, anthers of stamens tipped down; 



D, bee entering flower; 



E, flower, natural condition. 



(After Lubbock, natural size.) 



Many grasses and sedges and all the evergreen trees have their 

 pollen distributed by the wind. In fact, near large pine forests 

 the yellow pollen fills the air and covers the ground at certain 

 seasons, forming what people call " sulphur showers." 



Protection of Pollen. Since pollen is absolutely necessary to the 

 plant, it has to be protected from rain and from insects which 

 would eat it and from those which are too small or too smooth- 

 bodied to carry it. Protection against rain and dew is secured by 

 the drooping or closing of the corolla, while unwelcome insect 



