University of Arizona 



Agricultural Experiment Station 



Bulletin No. 79 





t.. 



Plant of Opunlia ^c«s tnrfica in the introduction t^rden, University Farm . badly injured 

 with a temperatur eof 21 degrees F. The illustration shows 6 months growth since the freeze. 



Cold-Resistance in Spineless Cacti 



By J. C. Th. Uphof 



INTRODUCTION 

 By J. J. Thornber 



Tucson, Arizona, December 1, 1916 



