Use of R. Corifolia Froebelii rohe (R. Laxa)

Has anyone used this for breeding. I am trying it as seed with r. arkansana. It is too early to say whether hips are solidly formed. Can someone hazard a guess at the ploidy of r. corifolia froebelii rohe? Its origins are in r. canina and is used or was used widely in Europe as a rootstock.

According to Modern Roses XI, R. coriifolia is pentaploid, i.e., has 35 chromosoomes. MR XI says that R. laxa is tetraploid (28), and that R. canina is found in both tetraploid and pentaploid forms.

It’s probably good to specify R. laxa Retzius if we’re talking about the really hardy species. The “laxa” used as rootstock is the canina rose, R. c. froebelii. The Rogersroses website had some confusion about this early on–I hope it’s entirely fixed.

Rosa Corifolia Froebelii (European rootstock) has been presented to me in the past as part of Rosa Canina but it belongs to Rosa Cinnamomeae. Where does Rosa Laxa Retzius (the Siberian giant) belong? Can it be that it is considered Rosa Cinnamoneae too and that is why there is still confusion about it? Other than the erroneous naming of Rosa Laxa for Froebeli?

I see that Beales classifies Coriifolia Froebelii as Cinnamomeae, but Krussmann classifies it as a Canina, as does Roy Shepherd. R. laxa Retzius belongs…in the back lot? Anyway, give it lots of room. I believe that it is included in the Cinnamomeae in all the classifications I’ve seen. The Cinnamomeae are usually diploid or tetraploid, but the Caninae are often pentaploid or higher and have a peculiar pattern of pollen/egg formation. Does someone know conclusively whether R. C. froebelii has this peculiarly Caninae pattern?