@Dave ....
There is no known sport of Cecile Brunner that is "armed with thorns". However, I can propose how you may have received a plant of CB with thorns.
When I volunteered to prune roses at the San Jose Heritage Rose Garden, I came across a few roses that had smooth canes and very thorny canes on the same plant. When I asked the curator of the garden how this could happen, I was told that the thorny canes were actually a "sport" cane of the plant, in that it had a different plant characteristic than was normal for the rose. (Every other plant characteristic ... foliage, bloom form, etc. was identical.) If bud-wood for propagation was taken from one of the thorny canes, the new rose would also be thorny. If bud-wood for propagation was taken from the smooth canes, the new plant would not have thorns in that those canes did not carry the mutation of the sporting canes.
I hope this makes sense.
Smiles,
Lyn
