94 BIG SPRING PRAIRIE. 
chiefly along the north and south road some distance 
west of the Cement Works. Ona few limited areas, 
the muck is deeper than commonly occurs on this 
prairie. Some years ago, a prairie fire burned the soil 
on one of these areas, and gradually a forest developed 
upon it. Southwest of Castalia Station, there occurs a 
low woods, which about a century ago, was doubtless a 
portion of the prairie. This woods contained principal- 
ly the following species: 
Populus deltoides (Cottonwood); Ulmus Ameri- 
cana (American Elms); Hicoria minima (Swamp 
Hickory); Quercus macrocarpa (Mossy-cup Oak); Celtis 
occidentalis (Hackberry); Tilia Americana (Basswood, 
or Linden); Acer (saccharinum or rubrum) (White 
Maple, or Red Maple.) Thus showing a close approxi- 
mation to the typical mesophytic forest. 
Since the artificial drainage of the northwestern 
portion of prairie, thickets of cottonwoods and willows 
are springing up, as the humus is thin and extensive 
marl deposits underlie it. This marl deposit forms a 
firm support for the roots. Thickets of the same 
species are also developing upon those portions where 
the surface soil has been disturbed and then aban- 
doned, but where dense sod occurs on areas formerly 
cultivated, tree seedlings seldom encroach. Certain 
portions are almost pure Potentilla fruticosa heaths 
with occasional Crataegus scattered about. The fol- 
lowing plants occuring on Castalia Prairie do not oc- 
curon Big Spring Prairie: Hypoxis hirsuta (Star- 
grass); Aquilegia canadensis (Columbine); Cypripe- 
dium candidum (Small White Lady’s Slipper); Hous- 
tonia (species) and Gentiana crinita (Fringed Gentian. ) 
The following common plants of Big Spring Prairie 
were not found at Castalia: Betula pumila 
(Low Birch) and Salix myrtilloides (Bog Willow), thus 
it isevident that Big Spring Prairie more closely re- 
sembles a Sphagnum Swamp than does Castalia 
Prairie. 
