POST-FLORAL MOVEMENTS 



405 



pollinated flowers a slight movement also takes place. 

 Fertilisation acts by inducing renewed growth in the 

 peduncle, and through this 

 the movement is accentu- 

 ated and accelerated. One 

 might be tempted to read 

 into the burying in the 

 foliage some protection 

 from rain or from birds, 

 but other species of Trop- 

 aeolum which do not show 

 the reaction do not seem to 

 suffer. In Euphorbia a 

 similar movement of the 

 pedicle of the female flower 

 brings the fruit hanging 

 over the edge of the 

 cyathial cup into a com- 

 pletely exposed position. 

 According to Schmitt 

 (1922) fertilisation is a 

 necessary prelude to the 

 post - floral movements of 

 Althaea and Digitalis. 



In the scarlet pimpernel 

 the peduncle before flower- 

 ing is sharply bent just 

 below the bud, so that the 

 bud nods ; it straightens 

 before the flower opens ; 

 after flowering it curves 

 downwards into a hoop, 

 bringing the fruit among 

 the leaves (Fig. 63). In 

 Agapanthus umbellatus the 

 bud stands vertically up- 

 wards, the flower is hori- ^^p- 63.— Scarlet pimpernel, show- 

 „^„. 1 .1 r -^ 1 ing pre- and post-floral move- 



ZOntal, the fruit hangs ments of the peduncle. Nat. size. 



