228 FLORA INDICA. 



streams, in sheltered valleys, are poplars, willows, and pro- 

 bably ash or walnut. Where the Aran enters Nipal, at Tin- 

 gri, the vegetation appears (from a small collection we have 

 received thence) to be similar to that of Kunawar. 



At Lhassa the country is open and stony, and without 

 trees, except such as are cultivated, just as in Western Tibet. 

 Of these, the apricot is the only one of which we have any 

 certain knowledge. Vines have been stated to grow in the 

 city of Lhassa (Humboldt, ' Asie Centrale '), but this has been 

 contradicted by all our informants. Further east, in the di- 

 rection of China, we learn from Hue and Gabet^s Travels 

 that the mountains are covered with forests, whUe towards 

 the south-east, iu the valley of the Yaru, a subtropical climate 

 is soon reached, tea, rice, and cotton being all cultivated. 



III. Eastern India. 



The axis, or watershed, of the great meridional chain which 

 is continuous with the Kouenlun must be sought as far north 

 as 35° N. lat., where it penetrates between the waters of the 

 Hoangho and those of the Yang-tse-Kiang. It is, however, 

 probable that the watershed of the Yaru river lies considerably 

 further south than this chain, and occupies a position nearly 

 parallel to that river, till it reaches 28° N. lat. in 98° E. long., 

 after which its direction is nearly north and south, and it be- 

 comes the axis of the Malayan peninsula, which separates Ava 

 and Siam on the one hand from Yunan and Cochin-China on 

 the other. 



To the north of this chain, in Tibet, lies a vast unknown 

 tract, in which the head-waters of the Yang-tse-Kiang perhaps 

 ramify, as well as those of the Tsa river, which is identified by 

 Chinese geographers with the Neay-Kiang of Cochin-China. 

 On the southern face of the chain the Dihong, the Brahma- 

 putra, and the Irawadi, have their sources. It may therefore 

 bo considered to be the boundary of India in this direction, as 

 the frontiers of Ava and China run nearly along it. 



