INTRODUCTION. 0] 
Care and identification of material. The identification, dis- 
tribution and arrangement of all the phanerogamic and vascular 
material collected during the season of 1891 was put in charge 
of Mr. E. P. Sheldon, whose ability and aptness for the work 
have been an indispensible assistance to the author. Under the 
direction of Mr. Sheldon, Mr. W. D. Frost and Mr. A. P. Anderson 
gave some time to the mounting and arrangement of such 
plants as were reserved for the general herbarium. This work 
occupied the entire autumn of 1891 and the winter and part of 
the spring of 1892. The large collections in the herbarium of 
the Department of Botany, which numbers not far from 62,000 
specimens, afforded excellent facilities for comparison when 
critical forms were under consideration. A few doubtful forms 
have been submitted to specialists, but in no cases have the 
determinations of Mr. Sheldon been modified. 
Citation of herbarium specimens. Every plant in the herba- 
rium of the survey is known by its collector’s name followed by 
a serial number. It thus becomes possible to refer to any plant 
definitely and decisively. Any mistakes in identification, if 
such should by chance occur, would thus be easily discovered 
and corrected by future workers. Under each species in the 
subsequent list of Metaspermae occurring native in the Minne- 
sota valley, all the herbarium material at hand is entered. Not 
only is the Minnesota valley material properly inserted, but all 
Minnesota specimens receive their place under the appropriate 
heads. Only such Minnesota specimens as belong to species 
not known or believed to occur in the drainage basin of the 
Minnesota river are excluded. In this way a complete account 
of the status of each species, in the herbarium, is presented to 
students throughout the state, and gaps or poorly represented 
species may receive attention from future collectors. 
In addition to the citation of all Minnesota specimens of 
Minnesota plants, so far as represented in the herbariums of 
the University, citations have been made from the personal 
collections of Mr. Sheldon, Mr. Wickersheim, of Idlewild, 
Lincoln county, and Judge Moyer, of Montevideo, gentlemen 
who have kindly contributed by the loan of their herbaria to 
our knowledge of the limits of species in their districts. The 
collection of Mr. Sheldon, cited as Herb. Sheld., is principally 
from the Ft. Snelling district; that of Judge Moyer, cited as 
Herb. Moyer, from the mouth of the Chippewa river; that of 
Mr. Wickersheim, cited as Herb. Wickersheim, from Lincoln 
