124 UNIVERSITY OF COLORADO STUDIES 



and Vicinity," by Dr. Francis P. Daniels. 1 These specimens have 

 not been seen by the present writers. 



Determination of Species. — Many of our specimens have in 

 previous years been submitted to Professor Aven Nelson of the Uni- 

 versity of Wyoming and the value of his determinations has been 

 very great for the present work. Recently, especially in the genus 

 Poa, some critical material has been sent to Professor A. S. Hitch- 

 cock, and the authors wish to acknowledge their indebtedness to 

 him. Two years ago Miss Louise Falk (now Mrs. W. W. Robbins, 

 of Fort Collins, Colorado) examined all of the Colorado grasses in 

 the University herbarium and her painstaking study brought to 

 light a number of errors made by our botanical staff in previous 

 determinations. The present writers have gone through all the 

 material here listed, have examined each specimen and have named 

 the plants in the light of all available information. 



The nomenclature used is with few exceptions that of Rydberg's 

 Flora of Colorado. 



Published Works Cited. — Since in any study of the area here 

 examined the student will necessarily make use of certain publica- 

 tions, these have been indicated with the page numbers for every 

 species. The works in the order of publication are : Flora of Colo- 

 rado, by P. A. Rydberg, published by the Experiment Station of the 

 Colorado Agricultural College, Fort Collins, Colo., 1906; New Manual 

 of Botany of the Central Rocky Mountains, by John M. Coulter, 

 revised by Aven Nelson, New York, 1909; Flora of Boulder, Colorado, 

 and Vicinity, by Francis P. Daniels, issued as a portion of University 

 of Missouri Studies, Science Series, Vol. II, No. 2, 191 1. The page 

 numbers given for Dr. Daniels' list refer to the reprint, which is 

 repaged. 



The Commonest Genera and Species. — In the area under con- 

 sideration the best represented genera as to number of species are 

 the following: Poa, with 15 species, Agropyron 10, Festuca 5, Bromus 

 5, Stipa 5, Muhlenbergia 4, Calamagrostis 4, Panicularia 4. 



1 University of Missouri Studies, Science Series, Vol. II, pp. i4g-45o, ion. Reprinted with change of 

 paging: i-xii and I-31X. 



