April, 1908.] 



The Vegetation of Cedar Point. 



321 



Secondary Species: 



Gleditsia triacanthos, Toxicodendron pubescens, 



Parthenocissus quinquejolia, Celastrus scandens, 



Prunus serotina, 

 Amelanchier sp., 

 Vitis vulpina, 

 Artemisia caudata, 

 Ruhus nigrohaccus. 



Juniperus virginiana, 

 Quercus velutina, 

 Panicum virgatum, 

 Andropogon scoparius, 

 Elymus striatus, 

 Asclepias syriaca, 



The various dunes scattered about in this section of the 

 peninsula exhibit considerable alternation as to the facies so 

 that there may be distinguished the Prunus virginiana Con- 

 socies, the Rhus aromatica Consocies, and the Ptelea trifoliata 

 Consocies. These three structures are, however, often mixed 

 indiscriminately on the same dune. 



Fig. 9. The Dune Section, looking southwards from the Lake Labora- 

 tory. To the left are the dunes and blowouts, between which and the 

 Bay to the right is the forest strip, here mainly consisting of the Ulmus- 

 Acer and Ailanthtts formations. (Photograph by Prof. Herbert Osborn.) 



One of the most noteworthy peculiarities of this vegetation 

 is the relatively large percentage of lianas and it is, in many cases, 

 due more to the presence of these plants than to the other vege- 

 tation that the integrity of the dune is preserved against the 

 vigorous action of the wind. In fact it appears that many of the 

 dunes were initiated bv the lianas or at least held bv them until 

 the invasion of the shrubs was accomplished. Especially notice- 

 able in this connection are Vitis vulpina and Parthenocissus 

 quinquejolia. 



