Chap. II. 



CLEMATIS. 



47 



footstalk caused it, in 12 hrs., to bend greatly, and 

 ultimately to such, an extent that the leaf passed to 

 the opposite side of the stem ; the forked stick having 

 been removed, the leaf slowly recovered its former 

 position. 



The young leaves spontaneously and gradually change 

 their position : when first developed the petioles are 

 upturned and parallel to the stem ; they then slowly 

 bend downwards, remaining for a short time at right 



Fig. 1. 

 Clematis glandulosa. 

 With two young leaves clasping two twigs, with the clasping portions thickened. 



angles to the stem, and then become so much arched 

 downwards that the blade of the leaf points to the 

 ground with its tip curled inwards, so that the whole 

 petiole and leaf together form a hook. They are thus 

 enabled to catch hold of any twig with which they 

 may be brought into contact by the revolving move- 

 ment of the internodes. If this does not happen, they 

 retain their hooked shape for a considerable time, and 

 then bending upwards reassume their original upturned 



