78 
IOWA ACADEMY OP SCIENCE 
The area from which this collection was taken includes prac- 
tically all that region, originally part of the forest belt adja- 
cent to the Des Moines river, which is drained by the ravines 
that converge among the ledge outcrops. The more restricted 
area, represented on the map (fig, 1) by the shadted part, is 
Pig. 1. — Map of the “Ledges” region. The shaded part indicates the area 
characterized by the sandstone outcrops. 
characterized by outcropping native sandstone rock. All of the 
plants listed as collected by the writer were obtained within 
this area at various times from September, 1914, until June, 
1915. Those specimens which are listed as collections by others 
may have been obtained within the boundaries of the unshaded 
part of the map. All the plants in the catalogue are repre- 
sented by specimens in the herbarium of the Department of 
Botany of the Iowa State College at Ames, The arrangement 
followed is that of Bngler and Prantl as used in Gray’s Manual, 
