INTRODUCTION. 
In 1901, Professor L. G. Carpenter wrote to Dr. N. L. Britton, 
director-in-chief of the New York Botanical Garden, inquiring if 
anybody connected with the Garden would be willing and had time 
to complete the determinations of the botanical collections accumu¬ 
lated at the Agricultural College at Fort Collins, especially during 
the time Professor C. S. Crandall was professor of Botany at that 
institution. As the author was well acquainted with the flora of 
the Rocky Mountain region, Dr. Britton referred the matter to 
him and at the same time gave him permission to undertake the 
work provided proper arrangements were made. After some corre¬ 
spondence with Professor Carpenter and Professor W. Paddock, 
such agreements were made as to make it possible not only to under¬ 
take this work but also to prepare a catalogue for publication. 
The work has taken more time than was expected at first, partly 
because it had to be done mostly in the spare time from the author’s 
official duties at the museum of the Botanical Garden, and partly 
because the author could not always secure the help he expected in 
the more mechanical work of recording the localities. The printing 
has also been delayed a good deal, and has been interrupted a few 
times for various reasons, so the work appears in print about a year 
later than was expected. 
The catalogue is mainly based on the collections of the Agricul¬ 
tural College at Fort Collins, mentioned above, and the herbaria 
at the New York Botanical Garden. Some additional records have 
been secured from other sources, as for instance, the National Her¬ 
barium at Washington, the Gray Herbarium at Harvard University 
and the herbarium of the College of Pharmacy of the City of New 
York. The author has also consulted the various publications on 
the flora of Colorado. The most important of these are: 
T. C. Porter and J. M. Coulter, Synopsis of the Flora of Colorado; 
J. M. Coulter, Manual of the Botany of the Rocky Mountain Region; 
T. S. Brandegee, Flora of South-western Colorado; Alice Eastwood, 
Flora of Denver and Vicinity; John Torrey’s report on E. James’ 
collection in Long’s Expedition; Asa Gray’s reports on the collec¬ 
tions of C. C. Parry, E. Hall and Harbour; Professor E. L. Greene’s 
various publications in Pittonia, Plantae Bakerianae and Leaflets 
XI 
