216 THE PLANT LIFE OF MARYLAND 



part of the Coastal Plain, belongs to this series of "Fall-line" 

 Gravel hills, and is identical with them in its vegetation. 



On the summits and higher slopes of the isolated hills in the 

 Gravel region the vegetation is almost as marked in character as 

 on the Serpentine Barrens. On the lower slopes and in the ravines 

 these features are largely obliterated by an approach to the flora 

 and groupings of the Loam areas of the Coastal Zone. In the 

 ravine bottoms the sandy elements of the gravel often form con- 

 siderable deposits and some of the plants characteristic of the sandy 

 swamps of the Eastern Shore may sometimes he found. 



The typical Gravel forest is made up of Chestnut and Chestnut 

 Oak, regardless of the age or stage of reforestation. The two are 

 usually pretty equally represented and together form from 60% 

 to 90% of the stand. On the summits of hills and well-drained 

 slopes the percentage is higher, on lower sloj>es and in level areas 

 it is lower. The commonest associated trees in the drier situations 

 are the Black Jack Oak, the Scarlet Oak, the Black Oak and the 

 Bed Maple. The Scrub Pine occurs sporadically in groves or small 

 groups, and the Pitch Pine has been observed in a few places, 

 where it has reseeded abandoned areas. 



There have been very few attempts to cultivate any part of the 

 Gravel areas of Cecil and Harford counties. There has been a 

 continuous cutting of the small timber for use in making charcoal, 

 which has prevented any improvement of the physical condition 

 of the soil through the return of a mature forest stand. The ex- 

 tensive "Barrens" of Cecil County arc traversed by the main line 

 of the Pennsylvania Railroad, which indeed follows the course of 

 the Cretaceous gravels and clays from Elkton to Washington, 

 thereby presenting to the traveler the least promising and least 

 improved section of the state. 



The Laurel (Kalmia latifolia) forms continuous thickets in many 

 of the Gravel forests and is in all places the predominant shrub. 

 On the summit of Egg Hill, in Cecil County, occurs the Rhodo- 

 dendron (Rhododendron maximum), which is not known from any 

 other station in the state east of the Blue Ridge. The occurrence 

 of this shrub here in a situation in which the soil conditions are 

 so radically different from those of its usual habitat is a striking 



