250 PLANT RELATIONS. 



vicinity of the seashore, where there are salty beaches, and 

 swamps and meadows ; (2) the margins of salt lakes, such 

 as the Great Salt Lake, the Dead Sea, or Caspian Sea, and 

 a host of smaller lakes : (3) about saline springs, which are 

 common among the numerous medicinal springs of water- 

 ing places ; (4) certain interior arid wastes, which probably 

 mark the position of old sea basins. An extensive area of 

 this last kind is known as the Bad Lands, which stretch 

 over certain portions of Nebraska and Dakota. In these 

 Bad Lands the waters are strongly alkaline. 



Comparatively few plants .are able to endure such con- 

 ditions. The family which has been able to develop 

 most halophyte forms is the family of chenopods, which 

 contains such prominent halophyte forms as the sam- 

 phire, seablight, saltwort, greasewood, etc. Associated with 

 these chenopods are certain portulacas, spurges, sedges, 

 grasses, etc. Such plants do not seem to be very sensitive 

 to climate, for the same halophyte species are found 

 everywhere, in all latitudes and at all altitudes. Probably 

 the so-called Kussian thistle, which is not a thistle at all, 

 may be cited as a notable illustration of a chenopod which 

 ranges through all climates. 



Halophyte vegetation is very open, and the ground 

 rarely seems to be covered. If the soil is always moist, 

 some plants which are not true halophytes may grow in 

 connection with the halophyte plants. If the soil dries 

 up easily, even a small percentage of salt presently be- 

 comes very conspicuous, and from such places every other 

 plant is driven out but the pure halophytes. 



There are many great families of plants which are never 

 known to grow in halophyte conditions, as for example the 

 great groups represented by oaks, hickories, walnuts, etc., 

 the nettle family, the rose family, the heath family, and 

 the whole display of mosses and lichens. On the other 

 hand, halophytes often grow outside of halophyte condi- 

 tions. To be a halophyte does not mean that other condi- 



