6 
BULLETIN 309, U. S. DEPARTMENT OF AGRICULTURE. 
tufts furnished the raw material for the first laboratory experiments 
with zacaton. 
DISTRIBUTION OF ZACATON. 1 
The genus Epicampes is exclusively American. About 16 species 
have been described, some of which, in the opinion of expert agros- 
tologists, would not retain specific rank under critical study. The 
ranges of the various species extend from California and Texas 
southward to" the Argentinian Andes Mexico is richest hi number 
of species, and there also the root-harvesting industry has reached 
its highest development. E. macroura has been reported from many 
widely separated localities from Texas to Central America. The 
collection in the United States National Herbarium embraces speci- 
mens from the following localities in Mexico: Canyon de San Diego, 
State of Chihuahua; San Luis Potosi, State of San Luis Potosi; 
Fig. 3.— Longitudinal section of calm, X 480, showing spiral and porous vessels, stereome, and thin- 
walled parenchyma. 
Sayula, State of Jalisco; Morelia, State of Michoacan; Nevada de 
Toluca, Ixtaccihuatl, Popocatepetl, Salazar, Cima, Federal District of 
Mexico; Eslava, State of Mexico; Mount Orizaba, San Marcos, San 
Andres, and San Miguel, State of Puebla. 
Zacaton grows most profusely in the mountain regions east and 
west of the City of Mexico. It is especially luxuriant in the districts 
around Sayula and Toluca, in the States of Jalisco and Mexico, 
respectively (it will be remembered that the original collection of 
Humboldt and Bonpland was made on the mountain of Toluca), 
while the finest quality of roots is now said to be harvested around 
Uruapan, in the State of Michoacan. The grass is generally consid- 
ered a pest, but a few attempts to subject it to crude methods of 
cultivation are reported to have given good results. It is perennial, 
1 Many of the data in this and the following paragraphs regarding distribution, climate, and the harvest- 
ing of the roots have been secured from Mr. A. McEwcn, Frederick, Md. 
