Contributions from the Department of Botany of Columbia University- 
No. 235. 
The North American Spe= 
cies of the Genus Ipomoea. 
By 
Homer Doiiver House, B. S., fl. A. 
Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philoso¬ 
phy in the Faculty of Pure Science of Columbia University. 
[Reprinted from the Annals of the New York Academy of Sciences, Yol. XVIII, No. 6, Part II, 
pp. 181-263. Published 11 May, 1908.] 
