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white. The distal part of the year-shoot dies before the next 

 vegetative period but persists as a point often thorny. The 

 year-shoots may be branched and are often twice branched. 

 The inflorescences are short racemes placed on branches of 

 secondary order. Under unfavourable conditions, for instance 

 on rocky ground, no long-shoots are formed but only short- 

 shoots. (A. compacta). 



The white or reddish flowers appear in April or May. 

 The fruit is a nut enclosed in the three-winged perianth. 



Salsola Arbuscula Pall. 



A characteristic and very variable plant. Its varied 

 aspect was described and illustrated so long ago as 1833 by 

 EICHWALDT. On clay it is a stunted, twiggy, stiff shrub with 

 short shoots and hard stiff leaves. But where it occurs on 

 moving-sand it may become a small tree with long pliant 

 shoots and leaves. In the sand-desert it varies in pliancy 

 and hardness, in length of shoots, and in hairiness of shoots 

 and leaves. It has very long roots which in the dune-valleys 

 may be seen exposed and stretching from dune to dune, 

 thus showing that some at least are horizontal. 



The best developed form (var. angustifolia Fzl.) will be 

 considered first (fig. 12.) As a tree it attains a height of 3 5 

 metres, with foliage greener and denser than that of any 

 other desert- plant in these parts; the stem is light-coloured 

 and elegant. It appears thus on the moving-sand, and here 

 also may be found specimens with fasciated branches, a 

 character which often accompanies luxuriant growth. 



Salsola Arbuscula is one of the most important plants 

 for sand-binding purposes along the Transcaspian railroads. 

 Small pieces of the stem are stuck into the sand and of 

 these 100 per ct. germinate, but many of them are injured 

 by lepidopterous larvae. In the course of two years the 

 plants attain a height of about 3 metres. The hardihood of 

 the plant in withstanding sand-drift has already been con- 

 sidered (p. 88). 



In vigorous specimens from the sand-desert the leaves are 

 7 centimetres long or rather longer. They are cylindrical 



13 



