LITERATURE CONSULTED 



1. Abrams, Leroy. An illustrated flora of the Pacific States , Washington, Oregon, and California. "Ophio- 

 glossaceae to Aristolochiaceae: or Ferns to Birthworts" 1: 1923. "Polygonaceae to Krameriaceae" 2: 1944. 

 "Geraniaceae to Scrophulariaceae" 3: 1951. "Bignoniaceae to Compositae" 4: 1960. 



2. Davis, Ray J. Flora of Idaho . Dubuque, Iowa: Wm. C. Brown Co. 1952. 



3. Fernald, Merritt L. Gray's manual of botany. 8th Ed. American Book Co. 1950. 



4. Harrington, H. D. Manual of the plants of Colorado . Denver, Colo. : Sage Book Co. 1954. 



5. Hitchcock, C. L. , A. J. Cronquist, M. Ownbey, and J. W. Thompson. Vascular plants of the Pacific 

 Northwest. Univ. Wash. Press. Part V. "Compositae ," by A. J. Cronquist. 1955. Part IV. "Ericaceae 

 through Campanulaceae, " by C. L. Hitchcock, A. J. Cronquist, and M. Ownbey. 1959. Part III. "Saxifragaceae 

 to Ericaceae," by C. L. Hitchcock and A. J. Cronquist. 1961. 



6. Kearney, T. H. , and R. H. Peebles, and collaborators. Arizona flora. Second edition with supplement 

 by J. T. Howell, E. McClintock, and collaborators . Berkeley: Univ. Cabf. Press. 1960. 



7. Little, Elbert L. , Jr. "Checklist of native and naturalized trees of the United States including Alaska." 

 Agr. Handb. 41: 1-472, 1953. Wash., D.C. 



8. Mason, H. L. A flora of the marshes of California. Berkeley: Univ. Calif. Press.' 1957. 



9. Munz, P. A. , and D. D. Keck. A California flora. Berkeley: Univ. Calif. Press. 1959. 



10. Peck, M. E. A manual of the higher plants of Oregon. Portland, Ore.: Binfords & Mort, PubUshers. 

 1941. 



11. Rydberg, P. A. Flora of the Rocky Mountains and adjacent plains. New York, published by the author. 

 1917. 



12. Tidestrom, I. "Flora of Utah and Nevada. " Contributions of the United States National Herbarium. 

 Smithsonian Institution, United States National Museum, vol. 25. Wash., D.C. 1925. 



13. Flowers, S. "Ferns of Utah. " Bull, of the Univ. of Utah, vol. 35, No. 7; Biol. Sci. ser. 4(6): 1-87. 

 1944. 



14. Clausen, R. T. " Botrychium . " Mem. Torr. Bot. Club 19: 22-107. 1938. 



15. Tryon, R. M. "A revision of the American species of Notholaena. " Contrib. Gray Herb. 179: 1-106. 

 1956. 



16. Tryon, A. F. "A revision of the fern genus Pellaea section Pellaea. Ann. Mo. Bot. Gard. 42: 1-99. 

 1957. 



17. Pfeiffer, N. E. "Monograph of the Isoetaceae . " Ann. Mo. Bot. Gard. 9(2): 79-232. 1922. 



18. Tryon, R. M. " Selaginella rupestris and its allies." Ann. Mo. Bot. Gard. 42: 1-99. 1955. 



19. Sudworth, G. B. "The spruce and balsam fir trees of the Rocky Mountain region." U.S. Dep. Agr. Bull. 

 327: 1-53. 1916. 



20. Critchfield, W. B. "Geographic variation in Pinus contorta." Maria Moors Cabot Found. Pub. 3. Cam- 

 bridge, Mass.: Harvard Univ. 1957. 



21. Cutler, H. C. "Monograph of the North American species of the genus Ephedra." Ann. Mo. Bot. Gard. 

 26: 373-429. 1939. 



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