12 ] The University of New Mexico 
New York Botanical Garden, North America Flora , various 
numbers. 
Shaw, G. R. The Pines of Mexico, 1909. 
Shreve, Forrest. The Cactus and Its Home. 
Standley, Paul. Trees and Shrubs of Mexico, 1920-1926. 
Trelease, William. Genus Quercus, Mem. Nat. Acad. Sci. 20, 
1924. 
Trelease, William. “The Yucceae,” Missouri Botanical Garden, 
Thirteenth Report, 1902. 
Considerable information was derived from articles 
on the economically valuable plants of Mexico. Among- the 
leading works and authors are: 
Conzatti, Casiano. Los Generos Vegetales Mexicanos, 1903. 
Cook, O. F. Numerous articles, especially on tropical food¬ 
stuffs. 
Cordero, y Seguro. Reseha sobre el cultivo de algunas plantas 
industriales, 1884. 
Diguet, Leon. Numerous articles, chiefly on cacti. 
Dodge, C. A descriptive catalogue of useful fiber plants of 
the world , 1897. 
Lloyd, F. E. Guayule, a Rubber Plant of the Chihuahua Des¬ 
ert, 1911. 
Martinez, Maximino. Las Plantas Mas Utiles de la Repub- 
lica Mexicana, 1928. 
Martinez, Maximino. Plantas Narcoticas de Mexico, 1925. 
Materia Medica Mexicana, 1900, various articles. 
Noriega, J. M. Contribution al Estudio de la Gobemadora , 
1923. 
Noriega, J. M. Historia de Drogas, 1902. 
Noriega, J. M. Las Plantas Mexicanas y Algunas Exoticas 
Productoras de Materias Colorantes, 1919. 
Nueva Farmacojiea Mexicana, 1904, 4th edition, various 
articles. 
Ramirez, Jose. Sinonimia Vulgar y Cientifica de las Plantas 
Mexicanas, 1902. 
Record, Samuel. Timbers of Tropical America, 1924. 
Rose, J. N. Notes on Useful Plants of Mexico, 1901. 
Safford, W. E. Numerous articles, especially on drugs. 
Because of the contiguity of Arizona, New Mexico, and 
Texas to portions of northwestern Mexico, it was possible to 
use a number of excellent studies prepared on the American 
areas. The most important of these studies are: 
