CLIMAX COMMUNITIES : PRESENT DISTRIBUTION 299 



six formations, each of which may be divided into from two to 

 nine associations. 15 



1. Rain Forest (Optimum formation) 



2. Seasonal Formations 



3 . Dry Evergreen Formation 



4. Montane Formation 



5. Swamp Formation 



6. Marsh or Seasonal Swamp Formation 



The subtropical climate of the southern tip of Florida and the 

 Gulf coast down into Mexico permits the growth of numerous 

 species with tropical characteristics and affinities. The palms, the 

 many broad-leaved evergreens, the mangroves, the many epiphytes 

 and lianas, and the sometimes jungle-like masses of vegetation are 

 all suggestive of tropical conditions. 



GENERAL REFERENCES 



E. LUCY Braun. The Undifferentiated Deciduous Forest Climax and the 



Association Segregate. 

 J. R. Carpenter. The Grassland Biome. 

 E E. CLEMENTS. Plant Indicators : The Relation of Plant Communities to ■ 



Processes and Practice. 

 R. E DAUBENMIRE. Vegetational Zonation in the Rocky Mountains. 

 J. W HARSHBERGER. Phy to geographic Survey of North A?nerica. 

 B. E. Livingston and E Shreve. The Distribution of Vegetation in the 



United States, As Related to Climatic Conditions. 

 H. L. SHANTZ and R. ZON. The Physical Basis of Agriculture : Natural 



Vegetation, in Atlas of American Agriculture. 

 V E. SHELFORD (ed.). Naturalises Guide to the Americas. 

 E SHREVE. A Map of the Vegetation of the United States. 

 J. E. Weaver and F. E. Clements. Plant Ecology. 



