DISCUSSION OF PLANTS 



71 



species of the western arid country produce their most 

 luxuriant growth in the presence of dangerous quantities 

 of alkali. Land upon which saltbush either bush or 

 weed grows best is generally light and free from alkali 

 in the top foot or so; but is underlain by heavier soil which 

 is likely to contain large quantities of alkali. Such soils 

 are seldom underlain by hardpan and are usually porous 



FIG. 12. THE LAST PLANT TO ABANDON AN ALKALI FLAT 



so that they may be reclaimed by flooding. Crops can as 

 a rule be grown on the soil on which saltbush occurs, but 

 there is likely to be a rise of alkali where great care is not 

 taken to prevent it. The alkali is likely to be of the white 

 type entirely, although it will grow with as much as 1200 

 parts per million (2) sodium carbonate in the soil. The 

 annual A triplexes are similar to the bushes in color and 

 appearance of the leaves but do not have the persistent 

 woody base of the latter. They range in height from 

 about i to 4 feet. Land upon which A triplex forms the 

 principal vegetation should be looked upon with suspicion 



