6 



AGRICULTURE HANDBOOK 495. U.S. DEPT. OF AGRICULTURE 



Figure 2. — Representative leaves of T>. 



to white. All six stamens are well 

 developed. In many varieties the 

 male flowers do not open or open 

 such a small amount that pollinat- 

 ing insects cannot enter. The pollen 

 of most varieties, as seen under 

 the microscope, is malformed or 

 aborted, but a few varieties, es- 



PN-4438 



alaia varieties. (Two-fifths actual size.) 



pecially of the wild or primitive 

 type, appear to be functionally 

 fertile. The female flowers (fig. 1) 

 are borne on long racemes from 

 the axils of the leaves. The flowers 

 are characterized by a prominent 

 trilocular inferior ovary from 8 to 

 15 centimeters long. The capsules, 



