SALINE AND ALKALI LANDS. 



545 



habit of growth, and flexible, somewhat wiry rootstock, 

 which enables it to persist even in cultivated ground, render it 

 a valuable plant as an alkali indicator. The salt-content 

 where Alkali-heath grows luxuriantly is invariably high, 

 ranging from 64,000 to 282,000 pounds per acre; salsoda 

 varies from 680 to 19,590 pounds; common salt ranges from 

 5,000 to 10,000 pounds. Such soils would not be benefited by 

 the application of gypsum, as the salts are already largely in 

 the neutral state. Of useful plants only Saltbushes and Tus- 

 sock-grass are likely to flourish in such lands,, when not too 

 wet. 



While Alkali-heath is thus one of the most alkali-tolerant 

 plants, it is at the same time capable of growth with a mini- 

 mum of salts (total salts 3,700 pounds, salsoda 680 pounds). 

 Where only a sparse growth of this plant occurs, therefore, the 

 land should not be condemned until a chemical examination 

 of the soil has been made. 



Alkali-heath is found on soils of very varying physical tex- 

 ture and degrees of moisture; while on soils of uniform 

 texture and moisture-conditions, but differing in chemical 

 composition, it varies with the varying salt-content. 



It has been found that Australian saltbush (Atriplex scini- 

 baccata) can be successfully grown on the " goose-lands," of 

 the Sacramento Valley, on soil producing a medium crop of 

 Alkali-heath ; it remains to be shown whether it will do 

 equally well on soils producing a dense and luxuriant growth 

 of the same. 



Alkali-heath is widely distributed throughout the interior 

 valleys of California ; a closely related form grows in the salt- 

 marshes of the sea-coast. 



CRESS A (Cressa cretica truxillensis Choisy) ; Fig. 88. 



Cressa soils show a low percentage of the noxious salsoda, 

 but comparatively heavy total salts (161,000 to 282,000 

 pounds per acre.) Common salt varies from 5,760 to 20,840 

 pounds per acre in four feet. The maximum is lower than in 

 the case of Alkali-heath, but Cressa seems to be much more 

 closely restricted to strong alkali than does the former species. 

 Cressa appears to be as widely distributed through the in- 

 terior valleys of California as Alkali-heath. The Cressa is a 

 35 



