Synopsis The state of Sikkim situated on the flanks of the Eastern Himalayas between 27010' - 28o5' N and 88030' - 890 E is bounded by Nepal in the west, Bhutan in the south-east, Tibet in the north and north-east and the Darjeeling district of West Bengal in the south. The topography of this pretty Himalayan state is varied. The altitudes range from 244 m to over 8598 m. Most of the 7300 sp km area is interlaced with jungle-clad ridges and deep ravines created by, and through which, the raging torrents of the mountain rivers speed and emerald valleys alternating with their terraced hill-sides and dense forests; a variety of plant beauties along with water-falls, rivulets, lakes and snow-capped mountains girdling the state in a protective embrace, embellish the land. The climatic, edaphic, altitudinal and biotic variations with their complex inter-relationship and species composition have resulted in different kinds of vegetation cover in the area. The forests cover ca 42.8% (3124 sq. km) of the total geographic area, of which 2260 sq km are protected and reserve forests. The state is very rich in biological diversity. It is estimated that ca 5000 species of flowering plants, ca 350 pteridophytes and ca 15 species of gymnosperms occur in this region. In addition to these a large number of non-flowering plants such as liver-worts, lichens, mosses, algae and fungi also occur.