Field Book of Western Wild Flowers—Margaret Armstrong
C. P. Putnam’s Sons, N. Y., 1915
Plants of Rocky Mountain National Park—Ruth E. Ashton
Government Printing Office, 1933
Revised edition under same title—Ruth Ashton Nelson in press, 1953
Colorado Cacti—Chas. H. Boissevain and Carol Davidson
Abbey Garden Press, San Marino, 1940
Rocky Mountain Flowers—Frederic E. and Edith S. Clements
H. W. Wilson Co., N. Y., 1920
New Manual of Botany of the Central Rocky Mountains—John
Coulter and Aven Nelson
American Book Co., Chicago, 1909
Manual of the Plants of Colorado—H. D. Harrington
Sage Press, Ft. Collins, Colorado—in press, 1953
American Wild Flowers—Harold N. Moldenke
D. Van Nostrand Company, Inc., N. Y., 1949
Meet the Natives—M. Walter Pesman
Denver, Colorado, 1943
Flora of Colorado—P. A. Rydberg
Ft. Collins, Colorado, 1906
Flora of Rocky Mountains and Adjacent Plains—P. A. Rydberg
New York, 1917
The Flora of Boulder County, Colorado—William A. Weber
University of Colorado Museum