70 BIG SPRING PRAIRIE. 



seedlings would appear. A diversified flora would 

 gradually develop from the natural introduction 

 of various seeds, until we should find just such a 

 flora as is found on the Minature Dune Complex, 

 which is the oldest of these dunes. It was formed 

 by the southwest, west, and northwest winds. The 

 south winds chiefly heaping up the sand carried down 

 from the Big Spring, which at present feeds the artifi- 

 cial lake represented in fig. 15. The surface is quite 

 undulating from the irregular arrangement of the sep- 

 arate dunes formed by the alternate shifting of the 

 winds. The highest portion of this dune complex is 

 about seven or eight feet above the surrounding level. 

 The humus overlying the dune sand is from eight to 

 twelve inches deep. The underlying sand is very fine 

 and a typical dune sand of unknown depth. The depth 

 of humus would indicate that this dune complex is 

 quite old, as would also the fact that this area was 

 densely wooded in 1832, when the Indian Reservation 

 was thrown open to settlement. Its age would also be 

 indicated by its diversified flora. 



The wooded area can be divided into the dune com- 

 plex proper, and a lower portion to the north and north- 

 east of it. 



On the dune complex proper, the most abundant 

 trees are: 



Ulmus Americana (American Elm); Quercus alba 

 (White Oak) ; and Acer saccharinum or rubrum (Silver 

 Maple or Red Maple.) 



Besides the above the following occur: 



Populus deltoides (Cottonwood); Prunus serotina 

 (Wild Black Cherry); Quercus imbricaiia (Shingle Oak); 

 Fraxinus Americana (White Ash.) 



On the low ground adjoining the following species 

 occur: 



Ulmus Americana (American Elm); Quercus pal- 

 ustris (Pin Oak or vSwamp Oak); Quercus platanoides 



