Has anyone used R. gymnocarpa in breeding? Apparently there are no registered hybrids using this species. This puzzles me because it has some wonderful traits: it’s almost thornless, blooms later than any other species, doesn’t Blackspot, has fragrance, blooms in large clusters on long arching canes, etc etc. Comments?
Hi Paul this one sounds intrigueing. Do you know the ploidy? I like that fact that it’s a CA native as well. Thanks, Robert
MR XI says that R. gymnocarpa is diploid. I haven’t tried to use it in breeding. I got mine from Las Pilatas nursery. Where did you get yours, Paul? It has a grace and charm that is lacking in other species found in California. The flowers and foliage are smaller than most other native species. Mine is perfectly healthy, but far from thornless. I’ve seen both thornless and very thorny individuals of R. spithamea, so it wouldn’t surprise me if there were variations in thorniness in R. gymnocarpa. It also wouldn’t surprise me if Las Pilatas misidentified it. The rose they sell as R. pinetorum is actually R. bridgesii.
There are a number of plants of R. gymnocarpa growing wild on my property, so its easily accessible to me. A botanist friend ID’d the species for me a few years back, but I haven’t used it before now. I am hesitant to get started with a diploid species rather than work with the primary hybrids we already have which are known to be fertile. Know what I mean?