Sri Lanka, the pearl of the Indian Ocean lays claim to eight of the current 911 UNESCO World Heritage Sites out of which two are endowed owing to rich biological diversity. Biological diversity or Biodiversity in simple terms is the variation of living beings including plants, animals and micro-organisms together with the variation exhibited by the non-living environment and genetic variation. Sri Lanka, even though claims for a relatively small land extent of 65,610 sq km, the geographical terrain, altitude and the climate of the islands display an ample variety that has resulted a extensive array in diversity, which has given rise to different floristic regions. Considering the topography of the country, three distinct peneplains are discernible. The lowest of these, the flat lowland peneplain covering about 75 percent of the land and is referred to as the `Low country' with the altitude rising from sea level to 300 m. Towards the south central parts of the country, the land rises steeply on all sides and the second peneplain, the `Mid country' is identifiable from 300m to 1,000 m. Further inland the land rises very steeply to form the south central mountain massif with several plateaus, which is the third peneplain or `Up country' (1,000 m - 2,500 m). The western, southern and western slopes of the central hills is fed by the southwest monsoons bringing ample rain from May to July and is referred to as the wet-zone while the northern and eastern regions that is fed by the north-east monsoon from December to January with a lesser amount is referred to as the dry-zone. Throughout these different zones one can see plants specially adapted to each set of circumstances, giving rise to a rich floral assemblage.