REFERENCES
Benson, Lyman; and Darrow, Robert: A Manual of Southwestern Trees and Shrubs; University of Arizona, 1944.
Benson, Lyman: The Cacti of Arizona; University of Arizona, Second Edition, 1950.
Black, Homer: Common and Larger Plants Near the Cavern Entrance; Carlsbad Caverns National Park; mss. 1944.
Cooper, Norman C.: Check List of Plants of Organ Pipe Cactus National Monument; mss. 1942.
Jaeger, Edmund C.: Desert Wildflowers; Stanford University Press, Revised Edition, 1944.
Joint Committee on Horticultural Nomenclature: Standardized Plant Names; Second Edition, 1942.
Kearney, Thomas H.; and Peebles, Robert H.: Flowering Plants and Ferns of Arizona; Government Printing Office, 1942.
McDougall, W. B.: Vegetation of White Sands National Monument; mss. 1939.
McDougall, W. B.: Check List of the Plants of Death Valley National Monument; mimeo. 1945.