536 SOILS. 



The plants which may best serve as such indicators in 

 California are the following: 



Tussock-grass (Sporobolus airoides Torr.), Fig. 82. 



Bushy Samphire (Allenrolfea occidentalis (Wats.) Ktze. ), 

 Fig. 83. 



Dwarf Samphire (Salicornia subterminalis Parish, and 

 other species), Fig. 84. 



Saltwort (Suaeda torreyana Wats., and 5". suffrntescens, 

 Wats.), Fig. 85. 



Greasewood (Sarcobatus vernuculatus (Hook.) Torr.), 

 Fig. 86. 



Alkali-heath (Frankenia grandi folia campestris Gray), 

 Fig. 87. 



Cressa (Cressa truxillensis Choisy), Fig. 88, perhaps 

 identical with C. cretica auct. 



Salt-grass (Distichlis spicata}, Fig. 89. 



TUSSOCK GRASS (Sporobolus airoides, Torr.) ; Fig. 82. 

 (" Buneh grass" of New Mexico). 



The three sets of Tussock-grass soil which have been 

 analyzed show that the total amount of all salts present is 

 in no case less than 49,000 pounds per acre, to a depth of 

 four feet; and that it sometimes reaches the extraordinarily 

 high figure of 499,000 pounds. Of these amounts the neutral 

 salts (Glauber's salt and common salt) are usually in the 

 heaviest proportion (Glauber's salt, 19,600 to 323,000 pounds 

 per acre; common salt, 3,500 to 172,800) ; the corrosive sal- 

 soda varying from 3,000 to 44,000 pounds. Tussock-grass 

 apparently cannot persist in ground which is periodically 

 flooded. It is of special importance because it is an acceptable 

 forage for stock. 



Tussock-grass is a prevalent alkali-indicator in the hot, 

 arid portions of the interior, from the upper San Joaquin 

 Valley, the Mojave desert, and southward; also through 

 southern Nevada and Utah as far east as Kansas and Ne- 

 braska. In the San Joaquin Valley it has not been found far- 

 ther north than the Tulare plains, although east of Reno it 

 occurs near Reno. Coville observes that in the Death Valley 

 region " it is confined principally to altitudes below i,oob 

 meters" (3.280 feet). Hillman, however, reports it from 



