10-i THE VEGETATION OF TEMPERATE AND ALPINE SIKHIM. 



used trade route to Tibet over the Ghoro La, the second highest pass 

 in Sikhini, being at an elevation of 17,000 feet. The northern side 

 of this valley is enclosed by an almost continuous precipitous spur, 

 broken in one place only by a deep forest-clad dejjression ; the range 

 on the other flank is more gently sloped, and is covered -with forest 

 and succeeding smaller vegetation, and is more diversified by ravines. 

 From 13 to 15,000 feet there is an impenetrable growth of rhodo- 

 dendrons and willows, with numerous small trees of Pynis foliolosa 

 and P. mkrophjlla ; and intermingled with grass under these bushes 

 is an equal luxuriance of herbs, such as aconites, Senecio^ Saxifraga, 

 Prunela, Potentilla, Polygonum, and thistles. Cnicus criophor aides, 

 which is moderately common in most valleys, is so abundant as to be 

 a jDerfect pest. From 14 to 15,000 feet the vegetation is more sparse 

 and scattered, being chiefly Rhododendron campanidatiim and R. antho- 

 pogon. 



From 15,000 feet to the pass the floor of the valley is broad and 

 swampy. Sedum of many species are common amongst the stones, and 

 Rheum nohilc, descending at last from what would be its more 

 congenial perches in other valleys, is found in numbers over the level 

 surface. Dense stiS' growths of Ejjhedra vulgaris, a plant of the order 

 Conifera?, abound on steep banks. Its presence is always a certain 

 witness of the proximity of the dry, arid regions of Tibet. Saxi- 

 frages, Allardia, Meconopsis horridula, Cgananthus, gentians, Saussurea 

 of three spiecies. Rhododendron nivaje, some grasses and sedges almost 

 complete the scanty details of the vegetation. Saussurea tridactgla, 

 growing at the foot of the ascent to the pass, is the last flowering plant 

 seen, and the rocks above, suffering continual denudation by the 

 weather, do not bear either mosses or lichens. 



Numbers of yaks are grazed in this valley up to 17,000 feet, cattle 

 range up to 13,000 feet. These animals possess sufficient instinct to 

 avoid eating the poisonous aconites, which at their highest attained 

 levels grow only to the height of the accompanying low herbage. 

 Goats and Tibetan ponies, from the information I gathered, share in 

 the same knowledge ; while sheep, strange to say, must be muzzled or 

 driven quickly through areas infested with these plants. One of the 

 rhododendrons, also, is equally poisonous to animals. The species 

 known to possess this property is Rhododendron cinnabarimmi. Honey, 

 which is collected in spring, but at no other time of the year, is said 

 to be rendered deleterious by the admixture of nectar from rhodo- 

 dendron flowers. 



By travelling up the main Lachung valley one anives at the flat 

 of Yeunitong, standing at the entrance to the Alpine zone extending 

 northwards to Tibet. A thick turf of grass covers the surface of 

 the flat, and on it grows a yellow Anemone {Anemone obtusiloba) with 



