.:V., : V' PREFACE. 



better knowledge of our plants, especially in the matter of geographical 

 distribution. M. S. Bebb has kindly looked over specimens of our Wil- 

 lows. The genus Carex has been corrected by Prof. L. H. Bailey. To 

 G. H. Hicks we are greatly indebted for assistance in revision, copying 

 and proof reading. 

 AGRICULTURAL COLLEGE, ) 

 Mich., April 25, 1892. \ 



