Hitchcock — Ecological Plant Geography of Kansas. 57 



or even more. The minimum temperature is probably 20" 

 higher in southern Kansas than in northern. 



In discussing the ecological plant geography, I will follow 

 the classification of Warming, dividing the various communi- 

 ties into four divisions: Hydrophytes, Xerophytes, Halo- 

 phytes and Mesophytes. 



Hydrophytes. 



Plants which love the water. They include water plants 

 and swamp plants. There are three groups : A. Plants 

 which are not attached to the substratum and may be sub- 

 mersed or floating. B. Plants attached to the soil but the 

 vegetative portion not extending much above the surface of 

 the water. They include submersed plants and also forms 

 with floating leaves. C. Swamp plants in which the vegeta- 

 tive portion extends into the air. 



The hydrophytic vegetation is distributed throughout the 

 State. There is some along every water-course, but the 

 amount found here is comparatively scant. In eastern Kan- 

 sas bayous and lakes left in old river channels have usually an 

 abundant supply of hydrophytes. Here and there are found 

 isolated swamps in depressions that are not directly connected 

 with a water-course. 



Where springs break forth there is usually a swampy area. 

 In western Kansas there are in many places perennial slow- 

 flowing streams of clear water which support a rich hydro- 

 phytic vegetation. In some localities, as in Meade and Kiowa 

 counties, large springs break forth into a small river at once. 

 Around these springs one finds besides a rich hydrophyte 

 flora, many species of eastern Kansas. One other habitat 

 for hydrophytes is found in the buffalo wallows. These are 

 depressions found on the high plains, which vary in diameter 

 from a few feet to many rods. 



CLASS I. FLOATING PLANTS. 



These are found only where there is open water. They float 

 on the surface or at a short distance below. 



Of flowering plants there are but a few species. Utricularia 

 vulgaris, Ceratophyllum demersum, 8pirodela polyrrhiza, 



