Circular No. 66, U. S. Dept. of Agriculture 



Plate Ii 





A. — Opuntia linguiformis, which reproduces vegetatively two types of plants, depending on whether 

 axial or lateral joints are used for propagation. B. — Proliferation of fruits in Opuntia puberula 

 caused by aphids. In other species insects cause the fruits to proliferate not into fruits but into 

 vegetative structures 



