Rosa carolina / virginiana

Happy New Year to those who have gone through it and to those about to, remember to drink lots of water before going to bed and put the Asprin bottle on the bench in the kitchen for easy access.

Question here. has any one noticed any difference in fertility between R. carolina/ virginiana. When using R. virginiana pollen everything stuck compared with R. carolina , nothing stuck. R. virginiana at the moment is amass with OP hips , R. carolina with zero hip set.

I found when using R. virginiana as a pollinator, 70% of offspring developed foliage structure similar to the pollinator. One of those which developed different foliage was this one ( Sympathie X R. Virginiana)

[attachment 218 103H40G.jpg]

Other seedlings of this cross displayed growth patterns which were upright and caney, leaf size was quite large(twice the size of R virginiana) with structure similar to the pollinator. With the one in the photograph, growth patterns are more horizontal, leaf size is quite small and quite glossy.

Crosses with tetraploid moderns and virginiana will likely be more successful than those across ploidy levels - virginiana is tetraploid whereas you can’t be sure about the others in that group. In fact I would expect carolina to be diploid.

Ploidy is only one consideration. Individual clones of anything differ greatly in their fertility and cross compatability so don’t pin yourself to just one. This is true, btw, of plants of the same cultivar meaning, for instance, that two Fashion clones may not be exactly alike.


In fact I would expect carolina to be diploid. [/quote]

Rosa carolina is tetraploid. I’ve never heard of a diploid clone.

Hi Mark; I have always thought R carolina was tetraploid, even way back in 1927 Hurst rated it as tetraploid. Looking on HMF R. carolina seems to be fertile both ways, so I am just wondering whats going on. Some times it can boil down to when to something simple, like pollinating very early in the season or waiting a bit longer. I will have to try this one in two stages next spring and see the results.

Dr. Walter Lewis and colleagues have a wonderful manuscript talking about diploid and tetraploid eastern North American species roses and suggest that different groups of diploids having had intermated and experienced polyploidization led to the generation of the higher ploidy species. This is based on molecular and other data. Here is part of the abstract that describes their conclusions:

In the east, two groups of diploids were found: one consists of R. blanda and R.

woodsii and the other of R. foliolosa, R. nitida, and R. palustris. Only eastern diploids are involved in the origins of the

polyploids. Rosa arkansana is derived from the blanda–woodsii group, R. virginiana originated from the foliolosa–nitida–

palustris group, and R. carolina is derived from a hybrid between the two diploid groups. The distinct origins of these polyploid

taxa support the hypothesis that the three polyploids are separate species.


One thing to keep in mind is that sometimes challenges we face in crossing may be to a particular genotype. Species are made up of many individuals (just like us as humans are one species). Some are more fertile than others and can make a better bridge in wide crosses. How many clones of R. carolina do you have? I received a clone from a friend as R. virginiana, but the more I learn, the more I suspect it is R. carolina. It has been a good parent, mainly successful as a male and I counted it and it is tetraploid. The seedlings sucker a lot like it and are hardy and pretty healthy. It is very choosy though for what pollen it accepts. It has not accepted modern shrub rose pollen. It has accepted pollen of the rose labeled as Rosa laxa at the MN Landscape Arboretum though, another Cinnamomeae section species.

Can you tell us more about your clone or clones? Do you know where it was collected from? Do you have pictures?



Howdy David and Happy New Year;

I read that article of Lewis and found it very interesting. The R. carolina I have, was given to me by a friend who lives north of me in a kinder climate. I have a feeling it may be temperature related, as it does not seem to tolerate the summer in the area where I live very wel. In the last couple of days temperatures here have been well over 100F and we are not really in the hottest part of our summer yet, it is not uncommon for us to get 113F or higher for long periods of time. R. carolina sulks quite badly in these temps, unlike R. virginiana which grows like a weed. I found the pollen fertility of my R carolina not good at all and as I said previously , what I pollinated, did not stick.

On an other note, I used R. sweginzowii this year as a pollinator, and the hip set has been unbelievable. Looking at the speed and plumpness of the hip set, you would not think there would be a ploidy issue. I should know if the crosses are viable in March , when germination starts.

When reading Lewis’s article, I looked up the diploid species in question which formed those tetraploids. The hybdridizing done with R. blanda , I like the results and offspring achieved very much. With R. nitida , the offspring Metis is awesome, really love the foliage. Have you seen this one growing at all?

Dave what did you want the pictures of?

Morning Warren, I think David Z would like a photo of the plant you got the pollen from.

Can you tell us more about your clone or clones? Do you know where it was collected from? Do you have pictures

Howdy Dave

David Z , here are a couple of photographs of R. virginina and R. carolina that I have. Top one is R virginiana.

[attachment 277 rvirg.jpg]

R. carolina, you can see the leaves folding as it is 106F outside at the moment.

[attachment 278 r.caro.jpg]

Hi Warren!!

Wow, the R. virginiana is sure beautiful with the foliage and clusters of hips. Thank you!! A friend of mine who has used a R. virginiana as well as it seems Joyce Fleming and some of her hybrids, that the clones of they used seem to allow warm colors to be transmitted in crosses with warm colored modern roses more easily they say than other single pink species. That is great that your R. virginiana is so heat tolerant.

Thanks again for attaching the pictures!!