— 74 — 



rarely higher than half a metre. The following are the most 

 common: Saxaul, Salsola rigida, Artemisia, Halostachijs and 

 Halimodendron. — In depressions salt-deserts are found which 

 are white with salt and produce their own particular vegeta- 

 tion closely related to that of the clay-deserts. 



The Growth-Forms of the Clay-desert in Spring 

 are Mesophytes, including Ephemeral plants and Perennials 

 with short-lived aerial shoots ; while in Summer (and of course 

 also in spring) we have Xerophytes, some small shrubs and 

 undershrubs, others perennials and long-lived annuals. 



As emphasized above, the chief difference between Clay- 

 desert and Salt-desert is that the latter lacks the spring- 

 aspect. 



CHAPTER 8 



The Formation of the Stone-Deserts. 



Antonow has recorded (see above p. 35) a formation which 

 he calls "Promontory or Stone-Steppe", said to be character- 

 ised by a special flora. This formation, according to the 

 nomenclature employed here, cannot be termed steppe but 

 must be called desert. Whether it is different from the clay- 

 desert as regards its growth-forms I cannot determine with 

 certainty because I have seen so little of the stone-desert. 

 But it must be more correct to keep apart that which cannot 

 with certainty be united, and therefore the stone-deserts will 

 be considered here as a special formation. 



The soil of the Stone-deserts is either rock, or gravel 

 with stones, or a conglomerate. The layer of conglomerate, 

 which is mentioned by Antonow, is probably the ordinary 

 tertiary conglomerate of stones cemented together by a loess- 

 like clay. Conglomerates of this kind are very common in 

 Turkestan (Walther) at the foot of the mountains and higher 

 up in the mountain-valleys. 



Where the cement is loess, what was stated about loess 

 as a soil (p. 57) holds good here. But the presence of numer- 



