FORMS OF THE PETIOLE 



Fig. 80. Amplexicnul leaves of Aster laevis. 



Fig. 81. Perfoliate leaves of Belhvort ( Uoularia pfrfoliata). 



Fig. 82. Connate leaves of Honeysuckle (Lon.icera sempirvirens). 



43. In Fig. 82 (Trumpet Honeysuckle) the leaves placed 

 opposite are joined together by pairs, base to base. Such 

 are connate leaves. 



44. The forms of the petiole, when the petiole exists, are 

 also various. Generally, it is merely a rounded, slender 

 stem, but you will often find it flattened. Have you e\er 

 noticed the structure of the Aspen (Poplar) leaf, which so 

 easily flutters in the gentlest breeze? Its petiole is flattened 

 vertically, so that its edges turn sky-ward and earth- ward. 

 Such a form of leaf-stalk is called compressed, and it must be 

 very nicely balanced in order to hold the blade at rest. 



43. When are leaves said to be connate ? 



44. What is the usual form of the petiole 1 Carefully describe the petiole 

 f the Aspen. 



2* 



