METHODS OF POLLINATION 



11 



Flowers of Several Types. — In some cases the stamens and 

 pistils are borne in separate flowers, as in the case of Indian corn, 

 cucumbers, melons, oaks, walnuts, and many others. These are 

 monoecious flowers. In other cases the two kinds of flowers are on 

 different plants and are then called dicecious. Familiar examples 

 are paper mulberry, willow, poplar, and muscadine grapes. In 

 such cases only the pistillate plants bear seeds. 



When stamens and pistils are in the same flowers, the flowers 

 are called perfect. (Fig. 6) We find perfect flowers in peaches, 

 plums, apples, pears, quinces, and the common bush fruits, Straw- 



Fro. 6. — Section of perfect flower showing pistil in center with growth from pollen grain 

 reaching the ovule. Stamens shed the pollen. Petals and sepals serve as protection and 

 sometimes attract insects to carry pollen. 



berries have perfect flowers in structure but in many varieties the 

 stamens do not develop pollen which will grow on reaching the pis- 

 tils. Such varieties must have others growing near them which 

 have good pollen. (Chapter XX). 



Methods of Pollination. — When flowers have both stamens 

 and pistils they may be self-pollinated and this is very frequently 

 the case. But there are very many varieties of orchard fruits in 

 which the pollen does not grow well on pistils of the same variety. 

 Thus we get better crops of fruit if several varieties of apples which 

 blossom at the same time, are grown together. This is often true 

 of peaches, pears and plums (Fig. 7). 



