194 



THE LEAF 



Plants which grow in excessively dry or desert regions, and Avhich 

 are thus ^'ery liable to suffer from excessive evaporation, ordinaril}- 

 have their leaves modified in some way so as to guard against this 



Fig. 562. Phyllodiuni of Aaicia. 503. Leaf of Acacia with blade present. 564. Loaf of Eichomia 

 with inflated petiole. 505. Cirrhose stipules of Smilax. 566. Aculeate leaf of Rubus. 567. Cirrhif- 

 (Tous leaf of pea. 568. Leaf of Tococa, its inflated petiole the home of ants. 569. Cirrhose petiole 

 of Clematis. 



tendency, and are called Xerophytic. They may become merely 

 reduced in size or may be otherwise modified, so as to reduce the 

 amount or the degree of activity of their epidermal tissue, or they 



