428 GENERAL MORPHOLOGY OF PLANTS 



608. Hydrophytes.* These are plants which grow in fresh 

 water or in very damp situations. The leaves of aerial hydrophytes 

 are very thin, have a thin cuticle, and lose water easily, so that 

 if the air becomes quite dry they are in danger of drying up even 

 though the roots may be supplied with an abundance of water. 

 The aquatic plants which are entirely submerged have often 

 thin leaves, or very finely divided or slender leaves, since these 

 are less liable to be torn by currents of water. The stems are 



Fig. 402. 

 Pond lilies, Harlem Lake, Central Park, N. Y. City. (After Murrill.) 



slender and especially lack strengthening tissue, since the water 

 buoys them up. Removed from the w r ater they droop of their 

 own weight, and soon dry up. The stems and leaves have large 

 intercellular spaces filled with air which aids in aeration and in 

 the diffusion of gases. Some use the term hygrophytes. 



609. Halophytes.f These are salt-enduring plants. They 

 grow in salt water, or in salt marshes where the water is brackish, 

 or in soil which contains a high per cent of certain salts, for 

 example the alkaline soils of the West, especially in the so-called 



* vdop = water, 0urov = plant, 

 f dXos = salt, <f>vrov = plant. 





