April, 1908.] The Vegetation of Cedar Point. 339 



This formation is apparently a rather rapid soil former and 

 with the elevation of the ground the more mesophytic conditions 

 permit the entrance of the following thicket formation, as around 

 the east side of the area of the Calamagrostis Wet Meadow to the 

 northwest of the Laboratory : 



The Cephalanthus-Cornus Thicket Formation. 



Facies: Cornus amomum, 

 Corn lis obliqua, 

 Ceph a I an thus occiden talis , 

 Rosa Carolina. 

 Principal Species: Sambucus canadensis. 

 Secondary Species: 



Salix cordata, Salix amygdaloides , 



Salix lucida, Calamagrostis canadensis, 



Polygonum convolvuhis, Solanum dulcamara, 



Dryopteris thelypteris, Platanus occidentalis, 



Ailanthus glandulosa, Ulmus americana, 



Rhus hirta. 



This vegetation should be classed rather as a mixed formation, 

 perhaps, than as a pure one, it apparently being made up of 

 various elements from the other thicket zones on the peninsula. 

 The predominating consocies is the Cornus amomum-obliqua 

 Consocies, while during the flowering period of the elderberry 

 the Sambucus canadensis Society determines in places a con- 

 spicuous aspect. 



Along the eastern shore of the marsh and wet meadow forma- 

 tions forming the northward extension of Biemiller's Cove, con- 

 siderable sand has blown over in places from the peninsula and 

 the bank rises in such places quite abniptly. At such points the 

 Rhus hirta Thicket Formation usually occupies this more xero- 

 phytic habitat and it, evidently, under such conditions, is suc- 

 ceeded by the Quercus velutina-imbricaria Forest Formation. 



Where the slope is more gradual, with a more hydrophytic 

 soil, usually also with more humus, the normal succession appears 

 to be from the wet meadow through the Cephalanthus-Cornus 

 Thicket Formation to the Ulmus-Acer Forest Formation. 



The Ailanthus glandulosa Forest Formation. 



An interesting example of an anomalous succession is afforded 

 in the near vicinity of the Laboratory and at a couple of other 

 stations on the peninsula by the Ailanthus glandulosa Forest 

 Formation which is rapidly developing along the shores of the 

 cove and Bay in the Dune Section. This Asiatic ruderal tree 

 now constitutes a prominent zone occupying the habitat of the 

 less hydrophytic of the thicket zones, although often displacing 



