178 OUTLINE OF PLANT GEOGRAPHY 



[mmediately south of the great barrier of the Himalaj^a lies 

 the extensive alluvial plain extending from the Arabian Sea to the 

 Hay of Bengal and comprising much of the land watered by the 

 Indus and < ranges. 



The great plain of the Indus is extremely arid, sometimes 

 absolutely rainless for a year or more. It is partly alluvial, partly 

 occupied by saline swamps, but a large part is a sandy or rocky 

 desert. Eastward the precipitation increases rapidly, and the 

 central, and especially the eastern portions of the Gangetic plain, 

 have a heavy rainfall. This is greatest about the head of the Bay 

 of Bengal, and the Ganges delta, where annual precipitation 

 exceeding 100 inches is not unusual. 



The central and eastern plains, which get the regular monsoon 

 rains, are extremely productive, and the most densely populated 

 portion of India. 



Most of the tropical part of India is comprised in the great 

 central plateau, enclosed by low ranges of mountains near the 

 coast, and a range to the north separating it from the Gangetic 

 plain. The two coastal ranges, the Western and Eastern Ghats, 

 converge southward, and are partially connected by transverse 

 hills. The great enclosed central plain is the Deccan, a plateau of 

 about 3,000 feet elevation. The northern portion of the Deccan 

 is semi-arid, as the moisture of the southwest monsoon is mostly 

 intercepted by the Western Ghats. To the south, conditions are 

 better, but nowhere in the interior of India are conditions such that 

 a tropical rain-forest can develop. 



The western coast (Malabar), receives the full benefit of the 

 southwest monsoon, and has an abundant rainfall, resulting in 

 evergreen forests of true tropical luxuriance. 



The conditions northeast of the Bay of Bengal are such that in 

 \-;mi and the Kasi hills, there is an excessively heavy rainfall. 

 One station, Cheripunji, has an annual precipitation of nearly 

 500 inches, exceeding this in some years, giving it the reputation 

 of the rainiest spot in the world. This region, however, lies out- 

 side the tropics, and the vegetation, although extremely luxuriant, 

 is to a great extent sub-tropical, rather than tropical. Separating 

 the Indus and Ganges plain from the plateau of the Deccan is a 



ries of hills or low mountains of which the highest, Mt. Abu, 

 rises above the Punjab plain to an altitude of 5.650 feet. Famous 



