PLA-NTS OF SOUTHERN NEW JERSEY. loi 



nate the intruders. Native weeds seem to gain the ascendancy 

 over the foreign ones, and then the forest and underbrush 

 gradually returns. 



In old fields grown up to Andropogon grass young pines de- 

 velop rapidly along wath sassafras, followed by various smaller 

 shrubs and herbs. In more arid sections we often find traces of 

 a clearing with a depression marking the location of a house all 

 covered with a growth of sand blackberry, Rnbus cuncifolius, or 

 sweet fern, Comptonia asplenifolia. 



Where cedar swamps have been cut or burned over there often 

 develops immediately an abundance of cattail, Typha latifolia; 

 wool grass, Scirpiis eriophoruiii, some distinctly Middle dis- 

 trict species and often Phraguiites, but soon the magnolia and 

 alder send up new shoots, quantities of chain ferns, JVoodzuardia 

 virginica appear, and later young cedars begin to grow, and 

 eventually the intruders are exterminated. 



In West Jersey (Middle District) cultivation is seldom 

 allowed to make a retrograde movement, and settlements are 

 seldom abandoned as they have been among the pines. In cer- 

 tain cases, however, I have seen examples of reforestation here 

 just as in the Pine Barrens, only that the sweet gum is the invad- 

 ing pioneer instead of the pitch pine. There is no evidence of 

 invasion of the Middle District by the Pine Barren element as 

 suggested by Dr. Hollick, the tendency being all the other way, 

 though, as already explained, only made possible by the agency 

 of man. The Middle District flora long ago occupied all land 

 where surface soil conditions were favorable right up to the Pine 

 Barren boundary and advances to-day only where those condi- 

 tions are extended artificially into the pines. 



In extensive Pine Barren settlements of long standing, as Vine- 

 land, Landisville, Hammonton, etc., a good many native plants 

 of the ^Middle district have followed the weeds and become estab- 

 lished where richer soil has been developed, and, while tliey are 

 listed in the following pages, the fact of their origin should be 

 borne in mind, and their presence at these stations should not be 

 regarded as evidence that these species were originally found in 

 the Pine Barrens. 



