io8 REPORT OF NEW JERSEY STATE MUSEUM. 



This submergence and the alluvial deposits along the Delaware 

 river valley may have hastened the destruction of the true Pine 

 Barren flora over this area and made soil conditions suitable for a 

 more rapid influx of the type of vegetation that at present pre- 

 vails there, though the isolated Pine Barren islands in the Middle 

 District would argue rather for the gradual encroachment of the 

 present flora coincident with a gradual change of soil. 



Just what elements have been instrumental in changing condi- 

 tions along the coast to make possible the existence of the coast 

 strip already referred to I cannot say, nor does it seem worth 

 while to theorize at present upon the possible explanations of the 

 presence of boreal species in the Pine Barrens or the recurrence 

 of so many boreal forms in southern Cape May. 



Lists of the coastal plain bog plants that occur in the Pied- 

 mont area in Pennsylvania have already been given on page 46. 



As to sandy ground plants characteristic of the coastal plain 

 which occur in similar soil in the Piedmont region there are quite 

 a number. 



The following I have found on the mica slate and sandy hills 

 of Chester or Delaware County, Pennsylvania : 



Quercus stellata. Phlox subulata. 



" marilaiidica. Galium pilosum. 



Rubiis cuneifolius. Diodea teres. 



Cracca virginica. Eupatorium verbensefolium. 



Stylosanthes elation Willugbaeya scandens (swampy 

 Crotalaria sagittalis. spots). 



A3cyrum hypericoides. Sericocarpus linifolius. 



Lechea racemulosa. lonactis linariifclius. 



Gaylussaccia frondosa. Chrj^sopsis mariana. 

 Asclepias amplexicaulis. 



Others occur on the serpentine outcrops as follows :* 



Pinus rigida. Meibomia obtusa. 



" virginiana. Strophostyles imibellata. 



Aristida oligantha. Pieris mariana. 



" purpurascens. Angelica villosa. 



Baptisia tinctoria. Eupatorium pubescens. 



Meibomia rigida. Aster dumosus. 



" marylandica. Phlox subulata. 



* From F. W. Pennell, Proc. Acad. Nat. Sci. Phila. 1910, 541-584- 



