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 oreight 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 atypical dune sand of unknown depth. Thedepth 
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 Ked Maple.) 
Besides the above the following occur: 
Populus deltoides (Cottonwood); Prunus serotina 
(Wild Black Cherry); Quercus imbricaria (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 Swamp Oak); Oweneits platanoides 
