Northerly spe- 

 cies of plants 

 in the Sayansk 

 district. 



Owing to the difficulties of penetrating into these mountain regions, the Urjankai 

 land has been able to remain so isolated, making the district about the sources of the 

 Yenisei a veritable terra incognita, with a population of natives, the so-called Soyotes, 

 well hidden and protected against any progress of foreign civilization. Only few regions 

 of the interior of Asia are so isolated and difficult of access as the land about the 

 sources of the Yenisei. As yet no part of the basin has been mapped out systematically; 

 the maps in existence are chiefly based upon the statements of the natives and, accord- 

 ingly, not only very defective but in a great measure even erroneous on essential points. 

 In every other respect the land is equally unknown. 



The Sayansk range itself lacks detailed survey, and the same may be said of the 

 encirchng border ranges of the basin. The headwaters of most of the rivers are 

 unknown, and the extensive regions between the Chua-kem and Bei-kem, the basin of the 

 Chua-kem and the Kemchik are still awaiting their explorers. The country is «New 

 Land indeed, where the mountains are nameless and the rivers all run God knows 

 where». 



Only in a couple of places the traveller is enabled to pass from Siberia into the 

 Urjankai land. One of the routes, the most difficult and unknown, lying across the 

 Algiac Pass and leading into the north-eastern part of the land, was followed by us. 

 This route is passable only a few months in the summer, being the greater part of the 

 year protected by ice and snow in the mountains and by the extensive, impenetrable 

 swamps and dense forest in the subalpine regions. The other one, a riding-path, lea- 

 ding from Gregoriewska via Usinsk, is not so difficult, and accordingly better known. 

 The access from the south, via Tannu-Ola, is easier, for which reason the land is also 

 in closer contact with Mongolia proper and China, to the latter of which countries it niay 

 also be reckoned to belong politically. 



In point of o r o g r a p h y, Ihe Sayansk district is connected up with Mongolia, forming 

 the north-western part of the Mongolian mountain table-land. The Sayansk mountains 

 may be said to form the first step from the Siberian lowland up to the Mongolian 

 plateau, and the Upper Yenisei basin Lo make up the first terrace; the Tanuu-Ola, con- 

 fining the basin to the south, forms the second step passing direct into the main table- 

 land. The Sayansk mountains are no real barrier in point of the floristic conditions, 

 the mountain ranges being crossed by lower, wood-clad passes by which the plants have 

 been able to spread. With the exception of the south-western declivities facing the large 

 Soyote Steppe about the Ulu-kem, the mountains themselves bear, both in floristic and 

 faunistic respects, a markedly arctic and subarctic stamp. 



This occurrence of northerly species so far south is especially interesting, being most 

 likely suggestive of survivors from the glacial period. For a corresponding flora is now 

 to be found in the subarctic and arctic portions of the Siberian lowland far to the north, 

 north of the dry, hot south Siberian steppe region. In former times, in a colder period, 

 this flora possibly also extended further to the south, over the large south Siberian 

 steppes, but in proportion as the temperature rose and the climate became drier after the 



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