20S THE PLANT LIFE OF MARYLAND 



quent include the Butternut, the Sweet Birch, the Sugar Maple, 

 the Linden, the Bed Oak and the Shagbark Hickory, all of which 

 are much more abundant or even characteristic in the Upper Mid- 

 land District and the Mountain Zone. The slopes on which these 

 subordinate species are most abundant are those along the larger 

 streams of the district, as Deer Creek, the Gunpowder and the 

 Patapsco. A rare tree found only on the slopes is the Umbrella 

 Tree (Magnolia tripeiala) the very large leaves of which make it 

 the most striking of the smaller forest trees. 



The most frequent and characteristic of the shrubs which are 

 found on the slopes but not on the topland are Hamamelis vir- 

 giniana and Hydrangea arborescens, the latter of which is more 

 abundant in the Upper Midland District. Very many of the her- 

 baceous plants found in the deepest shade or in the soils of highest 

 humus content in the topland are also characteristic of the slopes. 

 The most general in occurrence of these are: 



Carex stricta 

 Aquilegia 'canadensis 

 A risaema triphyllum 

 Am rum can ad en se 

 Dryopteris marginalis 

 Adiantum pedatum 

 Asclepias quadri folia 

 Juncoides campestre 

 Collinsonia canadensis 

 Scirpus planifolius 

 Bracli yelytru m erectu m 

 Salvia lyrata 

 Wash i ii;iton ia longistylis 

 Hydrophyllum virginicum 

 Galium tinctorium 

 ( 'arex costellata 

 MUella dipliylla 

 Solidago flexicaulis. 



