88 - 



But when it grows in the moving-sand desert, it becomes a 

 small tree, more than 4 metres high, and with long, pliant 

 shoots and leaves (comp. fig. 12 and fig. 38). The foliage is 

 comparatively rich; it is a green tree sufficiently dense to 

 cast a shade. 



The plant is very hardy and can endure being covered 

 by sand, a process which only hastens its already precocious 

 growth, and (according to PALEZKIJ) roots are formed from 

 the buried parts of the stem. He also states that he has 

 measured roots 15 metres in length, many of them horizon- 

 tal. Whether suckers are formed from them I do not know. 

 I have seen a tree from which the sand had been blown 

 away, so that it had fallen and lay on the slope of a dune 

 with some of the branches buried. The plant, however, was 

 perfectly fresh, still fixed by its roots and it had given off 

 new roots from the buried branches. 



Salsola snbaphylla is somewhat similar in appearance, 

 but has coarser and less dense foliage and neither in height 

 nor age does it come up the other species. Somewhat saline 

 soil is the most favourable for this plant. 



Both species blossom freely in the late summer and in 

 September they bear large clusters of broad-winged perianths 

 carrying the fruits. 



These two species, particularly the former, play an im- 

 portant part in the operations for binding the sand along the 

 railways. 



Calligonum (figures 11, 27, 28) and Eremosparton aphyl- 

 him (figures 23, 24) are both leafless i. e. the leaves are re- 

 duced to quite small scales, and both are shrubs or small 

 trees attaining a height of about 4 metres. They have long 

 roots (PALEZKIJ measured roots of 4,25 metres in a year-old 

 specimen of Calligonum Caput Medusae) and both plants can 

 form root-suckers. 



They are both sand-plants Calligonum, however, not ex- 

 clusively and they endure the sand-drift very well. Of the 

 many species of Calligonum (see list in chap. 12), C. Caput 

 Medusae is the most important. It flowers in May or June 

 and already in June one finds the curious globular reddish 

 fruits set along the slender twigs. The fruits are achenes 



