To all those who work or worked with R. foliolosa, the pink version:
For a short time now I have been observing a bud mutation on my R. foliolosa.
For me it is the first time. The growth abnormality is as usual limted on one shoot. It is noticeable that the leaf blade is much wider, larger and the leaf has consistent only 5 leaflets so far.
My question is, if this change in characteristics is an exceptional phenomenon on R. foliolosa or does this similarly happen more frequently? Depending on the rarity situation, I would try to secure the mutant via grafting or if necessary also via cutting, in the hope that one method will work.
What do you think, is it worth a try at all? Many thanks for support!
My experience is limited to just a few R. foliolosa, but I certainly haven’t seen anything looking like that. What strikes me is not so much the reduced number of leaflets, but the overall extreme difference in shape and color of the leaflets and leaf. It really doesn’t resemble the species at all. Is your plant grafted, by any chance? It would be very unusual, but if it is, maybe there is a chance that it is actually a graft chimera. If it happened to be that, it would definitely be worth preserving, and the interesting and variable features might extend beyond the foliage. I’m not sure that there has ever been a graft chimera reported in roses.
The true species form is understood to be white, whereas the pink forms in circulation are considered hybrids, probably with palustris in the wild populations. I don’t know if that lends anything to understanding your mutation or not, nor do I know how widely accepted that interpretation may be. It is regardless interesting.
All questions about the origins of pink-flowered R. foliolosa in cultivation aside, to me, the foliage in that photograph doesn’t really resemble anything in Sect. Rosa (syn. Sects. Cinnamomeae/Carolinae). Even my most odd-looking R. palustris, evidently an extremely variable species, doesn’t quite approach anything like this. I would have guessed something in Synstylae/Caninae if I were asked to make an ID.
As for the suggestion that pink-flowered R. foliolosa in cultivation are necessarily hybrids, I am generally skeptical because flower color is a highly unreliable distinguishing characteristic for determining species boundaries; I also can’t recall any other instance where the curling of stipules was regarded as a taxonomically informative character, but perhaps there is something to that in this case. Simon Joly & Anne Bruneau found that narrow leaflets (terminal leaflets less than 9 mm in width) and short pedicels were the most useful traits for distinguishing R. foliolosa from other species in their analysis, and made no mention of stipules [Delimiting Species Boundaries in Rosa Sect. Cinnamomeae (Rosaceae) in Eastern North America, in Systematic Botany 32(4):819–836. 2007.] It would require more careful scientific investigation to prove that the species does not include such pink-flowered individuals.
For what it’s worth, after examining my (pink-flowered, cultivated) R. foliolosa and an otherwise rather unusual clone of R. palustris from Florida, I can confirm that at least this clone of R. palustris does have incurved stipules–they roll inward to form a sort of tube. This is not the case with my R. foliolosa, however. The terminal leaflets of the R. foliolosa also appear to be within expected parameters, except maybe on vigorous young shoots (which would not be ideal for making taxonomic determinations anyway).
Here is my R. palustris, clearly showing curled stipules:
It appears that the stipules in the photo that Roseus provided are not curled, either. My plant’s flowers are also not “intense red,” so maybe there was a misidentified clone sold by Hillier Nurseries, but that individual may be a red herring when it comes to understanding the range of characteristics found in R. foliolosa.
