Pearl Sutton wrote:They certainly look like it.
Check that they spore print black, but I'm 99% sure that's them.
I have a thornless blackberry. It makes big canes (6 feet tall), tho rarely grows new leaves from old canes, and makes occasional fruit (so sweet you really have to mix it with something sour) but it is still coming off the same base that I planted five or six years ago. The thornless raspberries have spread out a bit (they are easy to control, just yank up what I don't want), but not the blackberry. That end of the garden tends hot and dry, so maybe that's the secret.