276 Journal of the Asiatic Society of Bengal. [N.S., XV, 
The greater part of the fuel used in the country is derived 
from its stems and roots and it is cut down remorselessly when 
near villages or encampments. When exposed to wind it is 
often blown, almost flat a each plant is situated on a small 
cult to pass between them without touching. In some ae 
of Seistan the dominant plant in sand-dunes is Peganum 
harmaea, round which small dunes are rapidly formed, the 
long trailing branches of the plant growing out on the lea- 
ward side. This plant also grows in the stony desert, but much 
less Juxuriantly. 
In the extreme south ie Seistan the sand-dune vegies 
tunity of making any but the most os observations on 
the flora. At some ine where there is surface water, the 
dunes are covered with coarse grass. 
V. THe VEGETATION OF THE HAamun-1-HELMAND. 
One of the most interesting features of Seistan from both 
a geographical and a biological point of view is the Hamun-i- 
Helmand. This is the basin, or rather series me basins, into 
which the waters of the Helmand drain. The northern basin 
contains a practically permanent lake of almost “Froah water ; 
the southern basins are usually dry or hold comparatively small 
bodies of brackish water. In floods, nerlye mainly from the 
rainfall and snows of Afghanistan, the water of the northern 
basin overflows into the southern ones pg thence through the 
Shelagh river, which is usually a dry bed with occasional pools 
of extremely salt water, into the Gaud-i-Zirreh, an immense 
shallow basin almost filled with salt that lies in the west of the 
Afghan desert. 
The Hamun is surrounded by reed-beds that cover hundreds 
of square miles. The outer parts of these beds are a phragmi- 
tetum, consisting of a reed exactly intermediate between 
aaa communis and P. Karka. It dies tthe more or less 
the permanent lake there are, in addition to the beds of Phrag- 
mites, - beds of Soienes littoralis and Typha angustata, all of 
which are per 
