FIVE IMPORTANT WILD-DUCK FOODS. \) 
varying length rise from the top of the stalk. From the same point 
three rather long grass-like leaves project below the fruiting clusters. 
Many members of the genus have a very similar appearance 
and it is not expected that nonbotanical observers can distinguish 
them. This is unnecessary, however, as tubers of the chufa for 
Fig. 8.— Seed-bearing and immature plants of the chufa. (Much reduced.) 
propagation may be obtained from most seedsmen. The tubers 
of the chufa are formed at the ends of scale-covered rootstocks. 
The plant is extremely prolific, cultivated forms usually producing 
100 tubers to the plant, and instances are known in which more than 
600 tubers were produced in one season from one tuber planted in 
the spring. 
19610°— Bull. 58- 14 2 
