46 



BOTANY 



^ B 



Flowers of the Lady Washington geranium showing the conditions of dichogamy; A, flower 

 with stamens ripe, but with the stigma not ready to receive pollen ; B, the same flower at 

 a later stage ; the stamens have withered, but the stigma is now ready to receive pollen. 



(1) The stamens and pistils may be found in separate flowers, 

 either on the same or on different plants. 



(2) The stamens may produce pollen before the pistil is ready 

 to receive it, or vice versa. This condition is called dichogamy. 

 Examples may be found in several of the flowers recommended 

 for study. 



(3) The stamens and pistils may be so placed with reference to each 

 other that pollination can be brought about only by outside assistance. 



In some flowers, as 

 is shown by the prim- 

 ula of our hothouses, 

 the stamens and pis- 

 tils are each of two 

 different lengths in dif- 

 ferent flowers. Short 

 styles and long or high- 

 placed filaments are 

 found in one flower, 

 ^ J. . , , , ., and long styles with 



Condition of stamens and pistils in the spiked loosestrife i i i 



(.Lythrum salicaria), short 01 low - placed 



