been omitted, if lacking additional information for identification. Pres- 

 ence or absence of a species in an area may be helpful indirectly by 

 elimination. Of course, many publications contain species distribution 

 maps. In the citations, those maps usually are indicated as illustrations. 

 The five volumes of "Atlas of United States Trees" noted below list 

 under Literature Cited other references with maps. 



Erdman, Kimball S. 



1970. Distribution of the native trees of Utah. Brigham Young Univ. 

 Sci. Bull. Biol. Ser. 11(3), 34 p., illus. (maps). Provo, Utah. 



Griffin, James R., and William B. Critchfield. 



1972. The distribution of forest trees in California. USDA Forest 

 Serv. Res. Pap. PSW-82, 114 p., illus. (maps). Pacific Southwest 

 For. and Range Exp. Stn., Berkeley, Calif. [1973] 

 Little, Elbert L., Jr. 



1971. Atlas of United States trees, volume 1, conifers and important 

 hardwoods. U.S. Dep. Agric. Misc. Publ. 1146, 9 p., illus. (313 maps, 

 folio). 



Little, Elbert L., Jr. 



1976. Atlas of United States trees, volume 3, miner western 

 hardwoods. U.S. Dep. Agric. Misc. Publ. 1314, 13 p., illus. (290 

 maps). 

 Little, Elbert L., Jr. 



1977a. Atlas of United States trees, volume 4, minor eastern 

 hardwoods. U.S. Dep. Agric. Misc. Publ. illus. (230 maps). 

 Little, Elbert L., Jr. 



1977b. Atlas of United States trees, volume 5, Florida. U.S. Dep. 

 Agric. Misc. Publ. illus. (maps). 

 Radford, Albert E., Harry E. Ahles, and C. Ritchie Bell. 



1965. Atlas of the vascular flora of the Carolinas. N.C. Agric. Exp. 

 Stn. (Raleigh) Tech. Bull. 165, 208 p., illus. (maps). 

 Viereck, Leslie A., and Elbert L. Little, Jr. 



1975. Atlas of United States trees, volume 2, Alaska trees and com- 

 mon shrubs. U.S. Dep. Agric. Misc. Publ. 1293, 19 p., illus. (105 

 maps). 

 Williams, John E. 



[1973.] Atlas of the woody plants of Oklahoma. 314 maps. Okla. Biol. 

 Surv. [Norman.] 



D. REFERENCES FOR GENERA AND FAMILIES 



A selected list of taxonomic monographs and similar references for 

 genera and plant families is included below. These publications contain 

 technical information seldom found in those limited geographically to a 

 State. Monographs of worldwide scope generally are omitted if the 



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