VESTAL: A BLACK-SOIL PRAIRIE STATION 355 
| Baptisia bracteata f, ld Silphium laciniatum, ch 
f Amorpha canescens, ch If Silphium integrifolium, ch 
f Petalostemum purpureum i, la Heliopsis scabra, ch 
| Tephrosia virginiana f Rudbeckia hirta, m 
& i Desmodium illinoense i, la Brauneria pallida (seldom 
. lf Lespedeza capitata seen in e. Du Page Co.) 
f, la Euphorbia corollata, ch f, la Lepachys pinnata, ch 
i Oenothera biennis lf Helianthus scaberrimus, ch 
i Asclepias tuberosa i Helianthus occidentalis 
1 Asclepias verticillata, ch i Helianthus Maximiliant 
1 Convolvulus sepium lf Achillea Millefolium 
i Lithospermum canescens, ch i Cirsium discolor 
The mesophytic prairie-grass association.—This type of prairie 
is more generally distributed within the area of study than is the 
Fic. 2 Fic. 3 Fic. 4 
. Fic. 2. A fragment in the mesophytic prairie-grass association, mixed grass 
consocies; a rather dry spot, Euphorbia corollata locally conspicuous; west of Elm- 
rst. 
FIG. 3. A moister spot close to the first, with Eryngium and Parthenium in 
flower, 
Fic. 4. At the county line; mesophytic prairie-grass, with Eryngium and 
Silphium balchlathhbdecsell Allium abundant and conspicuous; behind is lower 
ground with A grostis and Glyceria. 
xerophytic prairie-grass. There are several well-defined repre- 
sentatives of the mesophytic association. One is dominated by 
the tall grass Andropogon furcatus, often with hardly any other 
