24 - 



cies suddenly disappear at the margins of the depressions 

 and all that is left is a meagre flora, frequently reduced to 

 two or three Chenopodiaceae , such as Brachylepis salsa, 

 Anabasis aphylla, species which are uniformly distributed 

 throughout the whole area. 



These changes in the soil -conditions are mainly 

 responsible for the variations in the general physiognomy 

 of the vegetation. They also bring into prominence certain 

 plant-forms which may be observed over considerable areas 

 and which furnish the features characteristic of the areas 

 or sub-floras into which the Aralo-Caspian countries may 

 be divided. 



There are five of these areas: 



1) The Stipa-steppe 



2) The Clay-deserts 



3) The Salt-deserts 



4) The Moving-sand-deserts 



5) The river Serafshan." 



The following is a summary of Borszczow's description 

 of these areas. 



1) The area of the Stipa Steppe is the most northern, 

 and extends from its southern boundary at the Mugodshar 

 mountains and the rivers Tshit-Irgis and Turgai, towards the 

 N. E. where it merges into the grass steppes of the southern 

 part of the Tobolsk government. The Stipa Steppe thus lies 

 outside of the area under consideration in this work. The 

 surface of the steppe is almost everywhere undulating. 

 Forests do not occur, but here and there are groves mainly 

 consisting of poplars and willows. The most prevalent plant 

 is Stipa capillata, then follows Festuca ovina. Besides these a 

 number of species are recorded: Amygdalus nana, Spiraea-spe- 

 cies, Ulmus campestris, Caragana frutescens, Poplars, Willows, 

 Betula and Alnus, Ranunculaceae, Dianthus and Silene, Eryngium, 

 TViYiia, Compositae (Cirsium acaule, Jnrinea, Saussurea, Echinops), 

 also Tulipa, Iris, Allium and Carex. About 10 per ct. of the 



