In case anyone has interest, We have found another "Double blossomed" Salmonberry as reported by E. Mundy in Vancouver 100 years ago. I don't know if others have been found in the interim. The flower certainly shows Salmon Berry's "Rose connection".
Yes, that is interesting. There are a few of these known to be discovered. In addition to the one you mentioned, there was one found in western Washington. That is the one that was first introduced into broader cultivation, so it was named 'Olympic Double'.
