10 



BULLETIN 58, U. S. DEPARTMENT OF AGRICULTURE. 



Well-developed tubers of the cultivated variety average about 

 three-fourths of an inch in length by three-eighths of an inch in 

 diameter when dried. Tubers from wild plants are usually much 

 smaller and have a greater proportion of fiber. The general appear- 

 ance of chufas and of tubers from a wild sedge are well shown by 

 figure 9. 



Chufas are known also by the vernacular names, earth almonds 

 and ground nuts, and the plant as nut grass and cache-cache. 



FIG. 9. Tubers of wild Cypcrus and cultivated chufas. (Natural size.) 

 DISTRIBUTION. 



The northern boundary of the natural range of the chuf a is marked 

 by the following localities: Southern New Brunswick, southern 

 Ontario, northern Nebraska, New Mexico, Arizona, and the Columbia 

 River Valley. The plant seems to be absent from most of the Great 

 Basin and Rocky Mountain regions. From the northern line specified 

 the plant ranges southward over the remainder of the continent. (See 

 fig. 10.) It is widely distributed in warm climates over the entire 

 world. 



