— 77 - 



These observations indicate that the vegetation of the 

 Stone-deserts is mainly characterised by xeropliytic stunted 

 shrubs and underslirubs. Wlaetlier spring-plants occur there, 

 I cannot say. 



The following are species found only in the Stone-desert: 

 Convolvulus fruticosus, Stellera Lessertii, Reaumuria fruticosa 

 and Atraphaxis compacta. all dwarf-bushes or undershrubs 

 with small and flat leaves. The following seem to be common 

 in the Stone-desert, though they also occur in other forma- 

 tions : Reaumuria oxiana, Salsola rigida, (one of the most 

 frequent) Arthrophijtum subulifolium, Artemisia sp., Convolvulus 

 eremophihis, Capparis spinosa. 



CHAPTER 9 



The Formation of the Sand-Deserts. 



The soil of this formation is sand, at least on the surface. 

 The sand varies in origin and age as stated in chap. 2 '), but 

 these differences do not seem to play any essential pai-t with 

 respect to the vegetation (Korshinsky p. 8). The different 

 aspects presented by the sand are of greater interest to the 

 botanist. These have been described by Mushketow, Radde 

 and Semenow, and the following survey of the various sand- 

 landscapes is based on the observations of these authors. 



1. Barchans, crescent- shaped, dirty yellowish or fawn- 

 coloured dunes of inland sand. Musketow states that they 

 are generally 30 — 40 feet (ab. 9 — 12 metres) high, and 

 may attain a height of a hundred feet (ab. 30 metres); Se- 

 menow gives 40 metres but I have rarely seen any higher 

 than 10 metres and Radde gives 30 — 35 feet (ab. 9 — 10 metres) 

 as the maximum. The sand-grains are rather small. Radde 

 (1899, p. 16) gives . 2 — . 3 m. m. as the average size for 

 Barchan-sand and Sand-steppe sand from Amu Darya and Kara 



V See moreover Romanowski p. 52. 



