64 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
but those with little or no botanical knowledge, were able to secure 
the specimens desired. Numerous persons connected with the 
various branches of scientific work in Washington as well as botanists 
and others throughout the country assisted, so that finally a very 
large suite of specimens was brought together. This material con- 
sists at present of about two hundred and twenty jars of specimens 
preserved in formalin, besides an exhaustive series of dried specimens, 
the whole being deposited in the National Herbarium. Canada, 
Alaska, and practically every State in the Union are represented, 
except the Territories of New Mexico and Arizona, where the genus 
is not known to occur. This material was forwarded to Washington, 
sometimes in formalin, but more often fresh and merely wrapped in 
oiled paper. As soon as specimens were received careful notes were 
made on the color of the various parts. Tracings of some of the 
leaves were drawn, seeds were selected from the ripe fruits and dried, 
and in general a careful study was made of any peculiarities exhibited 
by the fresh plants. All but one of the species finally recognized 
were thus studied in the fresh condition. By the year 1904 enough 
material had been brought together to permit the determination of 
all but two of the nineteen forms of Nymphaea now known to occur 
in America. At this time pressure of other duties, necessitating 
several prolonged absences from Washington, made it impossible for 
Mr. Miller to continue the task of completing and publishing a 
revision of the genus, though he had written out the key to the 
species essentially in the form in which it now stands. At Mr. 
Miller’s request, Mr. J. H. Painter prepared to take up the work of 
elaborating the paper and procuring such additional material as was 
needed, but in December, 1908, this was interrupted by Painter’s 
tragic death. During the past year it has been resumed and brought 
to completion by Mr. Paul C. Standley, under whose authorship 
jointly with Mr. Miller’s the paper is now printed. 
AUTHORS’ INTRODUCTION. 
MATERIAL STUDIED. 
As stated by Doctor Rose, dry herbarium material is of little value 
for the study of this genus. When the species are once known, how- 
ever, most of them can be recognized in the dried state. Conse- 
quently, we have examined all the herbarium material available, 
with the result that we are able to map the areas of distribution of the 
better known species with some detail. In addition to showing the 
distribution of the various species upon outline maps, we have listed, 
with name of collector and date and locality of collection, all the 
specimens examined. These include all the material in the herbaria 
