60 



Certain forms of the sand-desert also have these two 

 aspects, and one finds here in places a quickly fading Spring- 

 vegetation; this is referred to in chap. 9. 



The spring- flowering period of the Clay-desert attains 

 its richest and finest development at the foot of the moun- 

 tains, for instance at the Persian Kopet Dagh and the western 

 Thian-Shan. In such places the amount of water is greater 

 than on the plains, and this causes in itself a richer vege- 

 tation of spring-plants. Moreover there is often cultivated 

 land at the foot of the mountains, and weeds from there 

 along with plants from the neighbouring mountain slopes 

 mix with the plants of the desert (KORSHINSKY see p. 36). 

 Such deserts, rich in vegetation, TANFILJEW calls Loess- 

 Desert-Steppe (the exact term used is not easily translated 

 from Russian!). "Semi-Desert" will be used to indicate them 

 in the following account. 



A sketch of such an area has already been given (p. 44). 

 In spring it certainly does not resemble a desert. Looking 

 at the mass of flowers one obtains an overpowering impres- 

 sion of richness, vigour and luxuriance. A closer examination, 

 how r ever, reveals traces of the desert nature. 



The plants do not form a close carpet or they do so 

 only in patches, whereas in other places the soil is quite 

 naked especially w^here salts crystallise out as a light dusty 

 covering which gives the soil a greyish colour. Here and there 

 among the fresh- green flowering plants one finds a grey Ar- 

 temisia or an almost leafless low chenopodiaceous bush; 

 they are still very backward in their development and one 

 can see that their season is still to come. In a few places 

 there are small stretches of moving-sands in the midst of 

 the flower-decked area; these are bare or scantily covered 

 with scattered coarse tufts of grass or low grey bushes. 



The following is a list of the plants which bloom during 

 the spring in the Semi-desert, together with a short summary 

 of the characters they have in common. 



Grasses are the principal constituents of the vegetation, 

 and of these Poa bulbosa is by far the most dominant, that 

 and the less important Hordeum secalinum are the only per- 

 ennial grasses. The shoots of Poa bulbosa have, as is well 



