JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. VIII MARCH 4, 1918 No. 5 



BOTAXY. — Plant life o)i saline soils.^ Thomas H. Kearxey, 

 Bureau of Plant Industry. 



The topic that I have chosen for consideration this evening 

 may not, at first thought, seem a very inviting one. Those 

 of you who are famiUar with salt marsh vegetation along the 

 sea-coast and with the plant life of so-called ''alkali" soils in 

 the arid part of the country'- must have been impressed with 

 their monotonous and rather unprepossessing aspects. Even 

 the mangroves of tropical and subtropical shores, the most 

 highly developed tj^pe of salt plants or halophj^tes, while in- 

 tensely interesting from a biological point of view, are by no 

 means so attractive to the casual eye as are many other forms 

 of tropical plant life. 



Nevertheless the halophytes have long been a subject of the 

 greatest interest to botanists. Study of this vegetation in rela- 

 tion to its environment leads us into some of the most intricate 

 problems in plant phj^siolog}'. 



ORIGIN AND NATURE OF THE SALINE COMPONENTS 



Soils containing an excessive quantitj^ of readily soluble salts 

 are for the most part confined eithei" to the immediate neighbor- 

 hood of the ocean or to arid interior regions. In the former 

 case the salinity of the soil is caused b^- periodical inundation 



1 Address of the retiring president of the Botanical Society of Washington 

 delivered February o. 1918. 



109 



