The area, dealt with, is bounded on the north and north-east by the snow line of the Himalaya, on the east and south-east by the Jumna, on the south by Central India and Scinde, and the west and north-west by Afghanistan and Baluchistan. The North-west Frontier Province has been included, because it was considered as forming part of the Punjab, and until a short time ago the districts across the Indus were part of the Punjab. Kashmir was included as it is impossible to form a satisfactory boundary in that direction, the greater number of the plants found in Kashmir grow in other parts of the Himalaya that are situated in the Punjab.