DFC 1 0 1910 
The Ohio W'aturalist, LIBRAR’ 
^ NEW v 
PUBLISHED BY BOTANIC 
The Biological Club of the Ohio State University. 
Volume XI. NOVEMBER, 1910. No. 1. 
TABLE OF CONTENTS. 
Dachnowski— A Cedar Bog in Central Ohio 193 
Detmers— A Floristic Survey of Orchard Island 200 
Nichols — A n Open Valley near Harrisburg, Ohio 210 
Hood— S ome Economic Monocotyls of Ohio 214 
Dickey— Meeting of the Biological Club 216 
A CEDAR BOG IN CENTRAL OHIO.* 
Alfred Dachnowski. 
Ohio is one of the states of a central region in which the 
dominant vegetation is the deciduous forest. Our forests are a 
type of plant formation, with a distinct physiognomy and growth- 
form, both of which are an expression of certain definite conditions 
of life. Deciduous forests characterize all regions in which there 
is an abundant rainfall well distributed through the growing 
season, a relatively high percentage of atmospheric humidity, and 
a relatively high annual sum total of temperature exposure. 
Before settlement by immigrants from Europe, Ohio was almost 
completely covered by dense forests. Here and there, in ravines, 
in depressions between morainal hills, on the highlands of water- 
sheds, were restricted areas of bog and marshland, sometimes 
many thousands of acres in extent, “filled in” ponds and lakes, 
another type of plant formations, of which the component species 
now tenanting such areas, and their relative proportion seemed 
more like an allusion to the distant north. Indeed they are 
relicts of a boreal vegetation which skirted the border of a great 
ice sheet covering almost all of Ohio. For reasons which will be 
stated in another paper these isolated areas of northern plant 
societies maintained themselves, and remained behind during the 
great migration of plants, while most of the plant societies adjusted 
to a northern climate, retreated northward with the glaciers as the 
winter conditions of the glacial period slowly changed to the 
present climate. 
*By permission of the State Geologist. Contribution from the Botanical 
Laboratories of Ohio State University, No. 57. 
: 93 
