133 



vegetation was richer: Salsola Arbuscula, Calligonum sp., Ar- 

 temisia, Saxaul, Salsola sclerantha. 



10. Desert at Ak Jar and northwards, on the left bank 

 of the Amu Darya. June 28. 1898. 



An undulating plain of argillaceous slate and loess cov- 

 ered with a layer of sand or gravel. The slate appears on 

 the surface here and there, forming small knolls. There is a 

 slight sand-drift and small hillocks of sand lie round the 

 base of the shrubs. The vegetation in places is uncommonly 

 rich, the distance between the shrubs being on an average 

 about 2 metres. The most common plants are: Salsola rigida 

 and Arbuscula (the clay-form, in flower) and Reaumuria 

 oxiana. This plant is more conspicuous than the others 

 because its foliage is darker and not so grey; it has fruits 

 and flower-buds, but no flowers open (2 p. m.). Lycium 

 ruthenicum rarely occurs (any specimens seen are over a 

 metre high), Saxaul is more frequent but thrives badly here 

 rarely attaining a height of 0,5 metre, many specimens are 

 quite red or reddish. The herbaceous plants are Salsola 

 sclerantha, Lepidium obtusum, and in other places: Halimoc- 

 nemis villosa and Suoeda sp. The latter sometimes scrambles 

 over Lycium and other shrubs somewhat like a liane; it 

 may attain a height of half a metre. 



The depressions are small "Takyr" (p. 55), the light- 

 coloured soil is stiff, regularly cracked by desiccation and 

 often lacks vegetation. In some places, however, Halimoc- 

 nemis villosa occurred abundantly; in one depression Haloc- 

 nemum strobilaceum grew luxuriantly, I measured a circular 

 tuft 140 centimetres in diameter. 



A similar gravel-plain at Pitnjak, not far from Ak Jar, 

 was sparsely covered with Peganum Harmala, Convolvulus 

 eremophilus and Anabasis salsa. No switch-bushes were 

 found here. 



11. A low mountain north of the fortress Ustyk (Bu- 

 chara) on the right bank of the Amu Darya. June 19. 1899. 



The mountain is terraced with low crags about 1 4 

 metres high. It consists of a soft stratified sandstone with 

 diverging layers mostly red in colour. Behind it stretches 

 the bare sand-desert. On the mountain the soil mainly con- 



