Chapter XLIII. 



Halophytes and Mesophytes. 



The adaptational type of vegetation known as salt vegetation, 

 or the halophytic group, is very sparingly represented in Min- 

 nesota. It reaches its best development in the mangrove 

 swamps of the seashore, and on salt-impregnated beaches or 

 marshes close to the ocean. A few salt plants are, however, to 

 be found in the state. In the Red river valley they are some- 

 times most prolific upon saline or alkaline soil. Here are en- 

 countered the sea-blites, the glassworts and the Russian thistle, 

 together with several salt-loving goosefoots, salt-loving purs- 

 lanes and grasses. One of the plantains is capable of growing 

 in salt marshes. The most general character of salt marsh 

 vegetation is its sparseness a character presented, for example, 

 by a growth of Russian thistles. Such plants are usually some 

 distance apart, not close together as in most other formations. 

 Salt plants, like many bog plants, are stamped with the xero- 

 phytic structural adaptations. The succulence of the glass- 

 wort and the great reduction of its leaf surfaces is distinctively 

 suggestive of the cactus type. The fleshy leaves of the goose- 

 foots and purslanes call to mind similar characters of rock or 

 desert succulents. If the body of a glasswort is chewed a 

 strong saline taste will at once be recognized and will serve to 

 demonstrate that salts are carried from the soil, where they 

 exist so abundantly, into the juices of the plant. The typical 

 salt-succulents are not ordinarily armed with thorns or spines 

 as are the typical desert-succulents. This may be because there 

 is not such absolute sparseness of vegetation in the general 

 locality and they are, therefore, not called upon to bear the 

 brunt of attack by hungry animals. 



Succulents in general. At this point it may be desirable to 

 bring together for comparison the different sorts of succulent 

 plants. They may be divided into two general groups, leaf- 

 succulents, such as the purslanes and century-plant, in which the 



