There was some discussion regarding this seedling at one time. Among the theories put forth was the suggestion that the rose used as pollen parent here called, "Californica nana", might in fact be R. spithamea.
Well, that makes it more interesting for me! I always wanted to work with that rose. I heard that the British californica breeding stock was something else instead. Do you know more about this?
No, just asking if you worked with it before. Any other species you have your eye on? I might be able to pull it off. I am to receive cuttings of Porceline du Chine- that will be fun!
Salix, I've worked on several species. I've concentrated primarily on evergreen types but there are others.
'Porceline du Chine' looks like a fun place to start. It will be interesting to see if it carries a gene for repeat. It would make things much easier if it does. Grow out a number of OP seedlings and see if any repeat. That will answer the question.
I know someone who's working with moyesii. That's one that should produce some interesting things.