Cholistan is an extension of the Great Indian Desert, which includes the Thar Desert in Sindh province of Pakistan and the Rajasthan Desert in India. Covering an area of 26,330 km2 , it lies within the south-east quadrant of Punjab province, between latitude 270 42' and 290 45' north and longitude 69° 52' and 730 05' east (Arshad et. al., 1995; Jowkaret. al ., 1996); 480 km long while its width varies from 32 to 192 km. The entire area is divided into two parts: Lesser Cholistan constitutes the desert margin consisting of a series of saline alluvial flats. alternating with low sandy ridges; its 20 per cent area comprises flat plains of hard clay, locally known as Dahars. Greater Cholistan is the name given to the southern part of the desert, which consists mostly of sand dunes, ridges and depressions. The word Cholistan is derived from a Turkish word, C/ia!, which means a desert; some historians believe that this name has been distorted from an Iraqi word. Chilistan, meaning waterless waste land. Cholistan is popularly known as Rohi. In a dialect still spoken in some part of Tibet, roh means a hill, from which the name Rohilla has been attributed. In fact Rohi is derived from the Pushto word roh, meaning waste sand or a sandy desert (Auj, 1987).