V 
Cnicus hillii, mentioned above, is named in honor of Prof. Hill, in recognition of 
his study of the genus Cnicus. 
We wish to make mention of the valuable assistance rendered by M. S. Bebb, 
Esq., Dr. Geo. Yasey and Professors H. F. Monroe, G. A. Brennan, Henry L. 
Boltwood, L. N. Johnson, S. S. Dodge, J. B. Williams, as well as many others 
among our local botanists and teachers of natural history. 
If we would keep pace with the continuous changes in the flora of Chicago 
and vicinity, it is absolutely necessary that constant investigation be carried on. 
On account of this, we hope that all local botanists will keep a record of all 
species they may discover which are not already catalogued, and of the new local- 
ities in which rarer forms may be found, as well as of the disappearance of species 
from localities mentioned in this work. And we make the request that they will 
send reports of their observations, accompanied by specimens, which will be re- 
turned if desired, to the Chicago Academy of Sciences. These notes will be used 
in the preparation of a more elaborate flora at some future date. 
The compilation of the Flora closed with the season of 1890, and additions 
since that time will be found in Appendix I. 
The Editoes. 
Academy of Sciences, Chicago, June 1st, 1891. 
