The Quisco Cactus
This is a species from South America which is so thorny that it is impossible to touch the finger to it at any point. Mr. Burbank has given it a place in his garden, along with many others, to see whether it shows a tendency to variation, and thus gives promise of possible modification. It is viewed, however, more as a curiosity than as the probable progenitor of a plant of economic importance.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 8 Chapter 6