VEGETAJ'ION TYPES. 



485 



II. Schimper's Vegetation Types. 



947. Another general classification of plants as regards their 

 adaptation to environment is that proposed by Schimper. There 

 are three kinds: 



1. Hygrophytes, which are especially provided with structures 

 favoring the loss of water, and which usually live under condi- 

 tions in which the danger of desiccation is excluded. 



2. Xerophytes, or dry-conditioned plants, which exist under 

 conditions which necessitate specialized structures for conserving 

 water and for retarding transpiration. 



3. Tropophytes. These 

 are plants which corre- 

 spond nearly with the 

 mesophytes of the former 

 classification. They show 

 a remarkable adaptation 

 to extreme conditions, and 

 represent the highest 

 physiological type of tem- 

 perate-region plants. 



948. Tropophytes. 

 Several types of tropo- 

 phytes are recognized. 



i. Deciduous trees and 

 shrubs. Through the 

 growing season these 

 plants bear foliage. The 

 transpiration stream is 

 strong, root absorption is 

 active, and transpiration 

 is abundant. The plants 

 in this condition are 

 mesophytes, and their life Fig - 488> 



/ Perennial plant ( Aralia nudicaulis) with a subter- 



relations are temperate, raneanrootstock, and annual leaf and flower shoot. 



With the approach of winter they shed their leaves and thus turn 



