458 PLANT DISTRIBUTION 



Arctic zones. Some or all of them are familiar to the 

 readers of this book. Reference to the accompanying 

 map will show the areas over which the several vegeta- 

 tion types are represented. They may be enumerated in 

 the following brief synopsis: (1) Deciduous Forest, 

 occupying most of the eastern United States, southeastern 

 Canada, parts of the Mississippi Valley, and extending 

 westward along the streams into the prairie region. 



(2) Coniferous Forest, occupying two rather distinct but 

 connected areas, the eastern one lying north of the decidu- 

 ous forest, extending north as far as southern Labrador 

 and northwestward to join with the western coniferous 

 forest. This western area includes first the entire Rocky 

 Mountain region from Yukon Territory south into New 

 Mexico and Arizona, and second the mountain ranges 

 lying near the coast from Alaska to southern California. 



(3) The Tundra or the Barren Ground, north of the limit 

 of trees and, what is nearly the same, the Alpine vegeta- 

 tion above the tree line on the higher mountain summits 

 both east and west. (4) The Grasslands occupying the 

 interior of the continent between the deciduous forests 

 and the Rocky Mountains. (5) The Desert occupying 

 the Great Basin and the arid plains and plateaus of 

 the southwestern United States. (6) Mixed Coniferous 

 and Deciduous Forests occupying the southeastern coastal 

 plain from New Jersey to Florida and west along the gulf 

 coast into Texas. (7) Chaparral, a shrubby growth 

 of evergreen plants occupying the foothills of the Sierra 

 Nevada and Coast Range Mountains of California. 

 Each of these large regions is, of course, suscepti- 

 ble of analysis into smaller areas each of which has 

 its own characteristics. For example, the southern ex- 

 tension of the Coniferous Forest has a fringe covered with 

 a dense growth of evergreen broad -leaved plants produc- 

 ing a vegetation type called Chaparral. The central 

 Grassland also naturally falls into two parts on the basis 

 of rainfall. The eastern part of it is far moister and 



