FLORA OF THE LEDGE'S 
77 
THE FLORA OF THE LEDGES REGION OF BOONE 
COUNTY, IOWA. 
WILLIAM W. DIEHL. 
INTRODUCTION. 
In the south-central part of Boone county is an area that 
possesses characteristic plants as well as peculiar geological and 
topographic features. This is located four miles directly south 
of Boone and extends for about two miles south toward and 
along the Des Moines river. Its name ‘^The Ledges” is appro- 
priate because of striking sandstone cliffs from ten to over forty 
feet in height, extending beyond the perpendicular in some 
eases as much as twelve feet. This ledge rock here comprises 
an island of younger massive sandstone surrounded uncon- 
formably by somewhat older Carboniferous layers, which are of 
different structure.^ The conditions peculiar to this restricted 
locality give the flora a distinctive character. 
The region has been of special interest at various times to 
students of plant life. Plants from ‘‘The Ledges” have been col- 
lected and studied chiefly by students from Ames. Thus the 
herbarium of the Department of Botany of Iowa State Col- 
lege possesses much material from that source. Hitchcock prob- 
ably made use of some material from ‘ ‘ The Ledges” in his Antho- 
phyta and Pteridophyta of Ames, Iowa. L. H. Pammel in ‘ ‘ The 
Character and Distribution of Forest Trees and Shrubs of 
Boone County, Iowa gives a list which was based largely 
upon collections and observations made at “The Ledges.” Bruce 
Fink collected lichens at The Ledges in 1903^. Collections pre- 
served in the herbarium of the Department of Botany have 
been made at various times by L. H. Pammel, R. E. Buchanan, 
C. M. King, Robert Combs, C. R. Ball, J. P. Anderson, J. V. 
Ellis, and others. 
THE SCOPE OP THE WORK. 
The scope of this paper is to list the Ptefidophytes and Sper- 
matophytes of “The Ledges” with an account of the plant char- 
acters of the region as revealed by a detailed study of a strip 
across a characteristic location. 
