456 



GENERAL MORPHOLOGY OF PLANTS 



type is very different. The types of vegetation, which fit plants for 

 growing in special regions or under special conditions, they have 

 taken on in response to the influence of the conditions of their 

 environment. While we find all gradations between the different 

 types of vegetation, looking at the vegetation in a broad way, several 

 types are recognized which were proposed by Warming as follows : 



621. Mesophytes.* These are represented by land plants 

 under temperate or moderate climatic and soil conditions. The 



normal land vegetation 

 of our temperate region 

 is composed of meso- 

 phytes, that is, the plants 

 have mesophytic f struc- 

 tures during the growing 

 season. The deciduous 

 forests or thickets of trees 

 and shrubs with their 

 undergrowth, the mea- 

 dows, pastures, prairies, 

 weeds, etc., are examples. 

 In those portions of the 

 tropics where rainfall is 

 great the vegetation is 

 mesophytic the year 

 round. 



622. Xerophytes.J 

 These are plants which 

 are provided with struc- 

 tures which enable them 

 to live under severe 

 conditions of dryness, 

 where the air and soil are 

 very dry, as in deserts or 



Fig. 414. 



Tropical vegetation, ferns and other plants growing 

 around and upon a column of lava, Hawaii. 



* pesos = middle, (f>vrov = plant. 



f Intermediate between the structures of desert and water plants, 

 dry, <J>VTOV = plant. 



