OTHER PLANTS 73 



Salt-grass (Distichlis spicata) occurs throughout the 

 world, being the most common plant found on alkali lands. 

 It grows well on land so free from alkali that some of the 

 common alkali-loving plants such as greasewood fail, but 

 can withstand and make a good growth with as much as 

 24,000 parts per million of total salts fn the soil. No 

 preference is shown for any of the alkali salts. The high- 

 est quantities found in soil on which it grew well are as 

 follows : 



Sodium carbonate 8517 parts per million 



Sodium chloride 4398 parts per million 



Sodium sulphate 2750 parts per million 



These quantities are only suggestive, however, as great 

 variations are found wherever the grass is found. It is 

 a poor indicator of alkali either quantitatively or quali- 

 tatively, but when taken together with other plants grow- 

 ing with it something of the nature of the land may be 

 indicated. 



Other Plants. A number of other plants which do 

 well on alkali soils, but which are not so distinctive as a 

 general rule, are the following: Rabbit brush or false 

 golden-rod (Chrysothamnus spp.) which is cluster-flowered 

 and woody-based; Plowman's wort (Pluchea camphorata 

 (i) DC.), a spicy or salt march Fleabane found in the 

 marshes of Texas and Mexico as well as on the eastern 

 and southern coast of the United States; little rabbit 

 brush (Isocoma veneta Grey) a perennial composite bush 

 about 1 8 inches high with a sparse, smooth, dark-green 

 foliage usually growing in deep loamy soils with a medium 

 salt content; spike weed (Hemizonia pungens), a yellow- 

 flowered spiny composite which grows in a dense mass 

 to the exclusion of most other plants on comparatively 

 weak alkali land with fair drainage; arrow or irrigation 



