48 THE PLANT LIFE OF MARYLAND 



those depressions are of interest as being the only natural ponds in 

 the state. They are often intermittent and usually too small to 

 have been noted on the topographic maps of the United States 

 Geological Survey, indeed the depressions themselves often occur at 

 such levels as not to be indicated by contour lines. A few of them 

 are shown on the St. Michaels sheet in the neighborhood of Wye 

 Mills. The slopes bordering the Sassafras and Bohemia rivers are 

 rather steep, there being at many points a rise from tidedevel to 

 60 ft. within half a mile. The greatest elevations of the Wicomico 

 terrace on the untapped divides are commonly from 60 to 70 ft. in 

 Queen Anne's County, and 80 to 85 ft. in Kent and southern Cecil 

 Counties. 



The portion of Cecil County lying between the Elk and North- 

 East rivers, known as Elk Neck, is made up mainly of Cretaceous 

 deposits and differs very much in its topography from the remainder 

 of the Eastern Shore. The surface is rolling and rises in groups of 

 rounded gravel hills several of which are over 300 ft. in elevation, 

 the highest, Black Hill, being 311 ft. 



The low elevation of the southern portion of the Eastern Shore 

 lias favored the development of areas, often many thousands of 

 acres in extent, in which the soil is saturated. Along the estuaries 

 these areas are subject to the influence of salt or brackish water and 

 are covered by grassy vegetation devoid of trees, — salt marshes. 

 Above the influence of brackish water the inundated lands along the 

 streams are forested, — river or stream swamps. Lying well back 

 from the streams on the poorly defined divides are areas subjected to 

 inundation by rain in wet seasons and in which the soil is at all 

 times saturated, whether or not there lie standing water, — upland 

 swamps* 



The flatness of the upland renders natural surface drainage 

 poor in all the more nearly level portions of the Eastern Shore, and 

 on the areas of Elkton clay particularly the heavy rains of the 



*The word marsh is used for a treeless plant community in a habitat with 

 saturated soil, and the word swamp for such an area in which trees form 

 the dominant vegetation. This is in accord with local usage on the Eastern 

 Shore and elsewhere in the Coastal Plain. 



