Thar Desert natural vegetation of this dry area is classed as Northwestern thorn scrub forest occurring in small clumps scattered more or less openly. Density and size of patches increase from west to east following the increase in rainfall. The natural vegetation of the Thar Desert is composed of the following tree, shrub and herb species: The endemic floral species include "Calligonum polygonoides", "Prosopis cineraria", "Acacia nilotica", "Tamarix aphylla", "Cenchrus biflorus". The Thar Desert is the most widely populated desert in the world, with a population density of 83 people per km. In India, the inhabitants comprise Hindus, Muslims, and Sikhs. In
Thar Desert hymn in the Rigveda mentions the Sarasvati between the Yamuna in the east and the Sutlej in the west, and later Vedic texts like Tandya and Jaiminiya Brahmanas as well as the Mahabharata mention that the Sarasvati dried up in a desert. Most scholars agree that at least some of the references to the Sarasvati in the Rigveda refer to the Ghaggar-Hakra River. There is also a small present-day Sarasvati River ("Sarsuti") that joins the Ghaggar. The epic "Mahabharata" mentions the Kamyaka Forest situated on the western boundary of the Kuru Kingdom (Kuru Proper and Kurujangala), on the banks of