Proof of the Pudding
Should any doubt remain that this curious plant with its absolutely smooth stem is really a blackberry, a test of the fruit will at once convince the most skeptical. Not only is this a thornless blackberry, but it is a fruit ofvery excellent quality. It has the peculiarity of maturing very late in the fall.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 6 Chapter 1