A PRELIMINARY SURVEY OF PLANT DISTRIBUTION IN 
OHIO.* 
John H. Schaffner. 
The following data are presented as a preliminary basis for 
field work in determining the natural plant areas of Ohio. It 
is hoped that the botanists of the State will begin active study of 
local conditions with a view to determine natural or transition 
boundaries as well as cataloging local associations. The distri¬ 
bution lists are based on herbarium material and more than 15 
years of sporadic botanizing in the state. Of course, distribution 
at present indicates to a considerable extent merely the distri¬ 
bution of enthusiastic botanists and their favorite collecting 
grounds. Nevertheless, enough has been done to indicate in a 
rough way the general character of our plant geography. 
The kind of data most important in indicating characteristic 
areas are as follows:— 
1. Meteorological data. 
2. Geology, including the nature of the surface rock and soil. 
3. Physiography and topography. 
4. The actual distribution of characteristic species of plants 
and to some extent of animals. 
In Ohio, the following important maps may be studied in this 
connection:— 
Meteorology. 
By Otto E. Jennings in Ohio Naturalist 3: 339-345, 403-409, 
1903. Maps I-XII. 
By J. Warren Smith in Bull. Ohio Agr. Exp. Station No. 235, 
1912. Figs. 3-14. 
Geology. 
By J. A. Bownocker, A Geological Map of Ohio. 1909. 
Topography. 
The maps of the topographic survey, not yet completed. 
Various geological reports. 
The eastern half of Ohio is a part of the Alleghany Plateau. 
The western half belongs to the great interior plain. In Ohio, 
the Alleghany Plateau consists of a northern glaciated region and 
a southern non-glaciated region. The latter apparently again 
divides into an eastern and western plant area. 
The interior plain consists of a southern glaciated calcarious 
region up to the Ohio River—Lake Erie water shed, and north of 
this of the very flat Great Black Swamp region and its margin. 
The northwestern corner apparently has a characteristic flora 
differing in many respects from the Black swamp area, and is 
probably to be regarded as a distinct region mostly beyond our 
borders. 
*Contribution from the Botanical Laboratory of the Ohio State Univer¬ 
sity. No. 86. 
