THE VEGETATION OF TEMPERATE AND ALPINE SIKHIM. 95 



THE VEGETATION OF TEMPERATE AND ALPINE 



SIKHIM. 



By GEOEGE a. GAMMIE. 



The following account of the vegetation of a restricted area of 

 Sikhim is based on observations made during journeys through the 

 interior of the country and its frontier tracts in the summer of '1892. 

 Some portions of this paper are verbatim extracts from a report 

 submitted to the Government of Bengal after my return. I have 

 not hesitated to avail myself of information from Sir J. D. Hooker's 

 invaluable " Himalayaa Journals " whenever I consider that the 

 opinion of a botanist of world-wide experience, even in such an early 

 period of his career, would throw a clearer light on many questions 

 which one with infinitely less knowledge and grasp of details would, 

 perhaps, attempt to answer by the use of vague conjectures. 



All tracts above an elevation of 10,000 feet are treated of as 

 Alpine. Under the term "Temperate Region" is included only the 

 country contained in the Lachen and Lachung valleys with their 

 ramifications up to 10,000 feet. 



It is true that many parts of Sikhim, such as the higher levels 

 of the spurs proceeding from the Singalelah and other ranges, are 

 temperate in their thermometric conditions, but the region to which 

 the designation is strictly confined is called so on botanical considera- 

 tions. Its climate, drier and more sunny in summer, favours the 

 existence of a vegetation in many ways radically different from that 

 of the moist outer ranges. As the botany of these has already been 

 dealt with in a former chapter, it will be only alluded to for the sake 

 of comparison when such a course becomes necessary for the more 

 perfect apprehension of any subject under discussion. 



The Temperate Region. — The hamlet of Cheongtong (Choongtam), 

 at the junction of the Lachen and Lachung rivers, marks the entrance 

 to this exceedingly interesting botanical area. The two valleys 

 through which these head waters of the Tista flow, run northwards 

 to the stupendous masses of the Himalayan axis which divides Sikhim 

 from Tibetan territory. They are separated by a lofty range extend- 

 ing southwards from Kinchinjhow, and even at its termination it is 

 10,000 feet in elevation. The floors of both valleys are nowhere 

 broad, and their flanks rapidly attain high altitudes, so that the 

 area in which temperate forms of plants flourish is circumscribed in 

 extent. 



TJie Lachung Valleg. — The trade route up the Tista valley passes 

 through tropical forests and cultivation as far as Cheongtou, where 



