Eastern South Asia region is bounded by Nepal, Sikkim, and Bhutan in the north, Bangladesh in the east, the Indian states of Uttar Pradesh and Chhattisgarh on the west, and the Indian state of Andhra Pradesh in the south. It is connected to the Seven Sister States of Northeast India by the narrow Siliguri Corridor. West Bengal is on the eastern bottleneck of India, stretching from the Himalayas in the north, to the Bay of Bengal in the south. The region lies in the humid-subtropical zone. The landlocked region of Northeast India includes the states of Assam, Arunachal Pradesh, Bihar, Mizoram, Manipur, Meghalaya,
Flora of the Indian epic period of the forest. In Geological Ages: palaeo-botanical evidence testifies to the fact that there were dense forests in India in the Permian period, 250 million years ago. A fossilized trunk of a tree found in the Raniganj coal-field is nearly 30 m long and 75 cm in diameter at the butt-end and 35 cm at the top-end. It has been named by Dr. Birbal Sahni as Dadoxylon, an extinct genus of plants. Fossil wood is found in several places in Madhya Pradesh and in the Siwalik hills along the Himalayas. Man was evolved in the beginning of Pleistocene Age, only