394 



PLANT PECULIARITIES 



partly in the water, lifting their leaves and flowers into 

 the air. 



Plants which live in the water are called hydrophytes 

 (hy'dro-fltes : Greek, hydor, water; phyton, plant). If 

 such plants have roots, they are little more than holdfasts, 

 for the hydrophytes do not need organs of absorption. 

 Most of the members of this plant society are without 



Figure 431. — Cat-tails and Arrow-leaf. 



mechanical tissue, for the water holds them firmly on all 

 sides. The alg?e lack a conducting system as well, for 

 their source of food is all about them. Waterlilies get 

 their oxygen and much of their carbon dioxide from the 

 air through their leaves, which float on the surface of the 

 water with the stomata on top. Air passages in the long, 

 slender steins convey air to the roots which lie in the mud. 

 Hydrophytes which lie under water have their leaves 

 finely divided to offer as much surface as possible to the 

 water and thus secure a full supply of oxygen. 



