ADVERTISEMENT. 
Tuts work is intended to facilitate the labors of botanists by 
furnishing references to all the published descriptions of species of 
the flora of North America, with a chronological arrangement of the 
synonymy, and is published by the Smithsonian Institution at the 
request of the leading botanists of the United States, who have also 
contributed to the expense of its preparation. 
The first part of the work is now published, as this covers the 
ground of Vol. I. of Torrey & Gray’s Flora of North America, and 
is complete in itself: the remainder will be printed as soon as the 
manuscript can be furnished by the author. 
JOSEPH HENRY, 
Secretary Smithsonian Institution. 
Wasuincton, March, 1878. 
