The recent post about Rosa blanda by Paul Guerts reminds me why, if the objective is not to develop thornless roses, why Rosa acicularis should be used instead of Rosa blanda or Rosa woodsii in breeding programs for cold hardy (Zone 2 - 3) roses. Yes, there is a ploidy problem in this species to overcome but that can be accomplished by crossing with diploid species or cultivars. If the pedigree of ‘Dornroschen’ is correct, potential ploidy problems crossing this species with modern roses can also be overcome relatively quickly.
‘Dornroschen’, by the way is comparable in cold hardiness to the Parkland series of roses. It is also very fertile as a pistillate parent and the seeds germinate relatively easily.
The advantage to using Rosa acicularis compared to Rosa woodsii or Rosa blanda is it is a more attractive shrub with larger flowers and leaflets. Furthermore, because of the work of Robert Erskine we have a couple outstanding selections (‘Aurora’ and ‘Kinistino’) to work with. These selections have flowers that are larger and deeper pink than normally seen in the species. The foliage is also more attractive.
Having said the above, using Rosa acicularis (or Rosa blanda and Rosa woodsii) in breeding programs, unless it is with Rugosas or other disease resistant types of roses (and even then there are problems in very warm and humid climates), the progeny will likely lack disease resistance. Because of this situation, I think it would be ideal to first develop species hybrids with the tough, disease resistant species from Europe and Asia. For example, Rosa beggeriana and Rosa fedtschenkoana. There has been little work done developing species hybrids crossing North American with European/Asian species. If it is done more, the results could prove very interesting and perhaps eventually advance the development of cold hardy, disease resistant roses.
The 2 seedlings of Rosa acicularis x R15 that I raised from what Henry gave me have absolutely fabulous foliage. There are TONS of pricles…but theyre soft and touchable. Also, the wild Rosa acicularis in my area is very well behaved. With the exception of Rosa californica, it is the only native species here that is aesthetic.
Take it for what its worth
I had always wondered why you advocated using an R.acicularis x diploid cross instead of using a zone 3 hardy tetraploid like R.arkansana. But now you clarified it for me. It
I was looking around the interenet and found an article about black spot resistance. I think it was posed here previously. One interesting thing about it was that they found r. acicularis nipponensis to be completely resistant to the 3 forms of blackspot they were testing with.
How hardy is nipponensis? Its a tetraploid, correct? How is nipponensis different from the r. acicularis that Paul is talking about.
Wondering if nipponensis would work with versions of r. acicularis with different ploidy.
The hybrid seeds Henry sent me had zero tip freeze here. We had a weird freeze in March after everything started sprouting, and it was not phased whatsoever.
I’ll never forget shrubs of Rosa acicularis ‘Aurora’ and ‘Kinistino’ growing next to each other on the property of the home where the originator of these two cultivars, Robert Erskine, lived the last years of his life. They were in full bloom with their deep pink almost red flowers (‘Kinistino’ has slightly deeper pink flowers) and it was a stunning sight to see. Rosa arkansana shrubs in full bloom, even though the flowers of some genotypes have interesting colour pattterns, can’t begin to compare in beauty.
One deficiency with Rosa acicularis is that there are only 3 - 5 flowers in each cluster. It’s possible in Rosa woodsii to have as many as 15 (as in one genotype I have collected, which I call ‘Profusion’). I intend to cross this Rosa woodsii genotype with Rosa acicularis ‘Kinistino’ to obtain a tetraploid that hopefully will be quite floriferous.
I’m responsible for getting Rosa acicularis ‘Aurora’ into the States. I intially shipped it to Greenmantle Nursery in California. That was 20 years ago. It’s my intention this fall to get ‘Kinistino’ into the States. Who wants it?
Rosa acicularis nipponensis has been changed to a separate species - Rosa nipponensis. Its bright pink flowers are more attractive than typical Rosa acicularis flowers. This species is at least cold hardy to Zone 3 and probably to 2.
I had nipponensis and lost it last Summer after several years.
The blossoms blow incredibly quickly but each one made a hip and the hips matured very very quickly. I never utilized it.
I have utilized ‘Dornroschen’ and am happy with the results though Dornroschen itself is susceptible to mildew.
The R. woodsii clone that Joan Monteith found and mentioned in the RHA newsletter may be very useful in a similar line of work. It is hexaploid and has wider leaflets and such than the diploid forms. She found it as an unusual variant among a patch of 2x R. woodsii. She sent me plant material of both and that’s how I confirmed this variant was 6x. It definately looks like the diploid R. woodsii morphologically for general hip and flower and leaf shapes. This 6x clone has unusual pollen. It has normal pollen that would be 3x and also 4n or 12x pollen as well. That is a clue to me that it may have been the result of a union between a 4n and 2n gamete itself from normal diploid R. woodsii. We don’t hear much about 4n gametes. In the process of meiosis the chromosomes are duplicated in a normal cell somewhat as if it was getting ready for normal mitotic division. So for this 6x plant the cell duplicates every chromosome having two copies of each of the 42 chromosomes for 84. Then going into meiosis, meiosis I divides the chromosomes to two nuclei with 42 each, and them meiosis II each of those get divided to 21 each. There is then four pollen grains that each have 3 sets of seven chromosomes (21) each. This 6x rose makes normal pollen the diameter of 3x pollen and also pollen that looks 12x as if none of the divisions happened and is 4n (all 84 chromosomes 12 x 7)! Perhaps it resulted from a diploid R. woodsii that had a 4n gamete (4 sets of chromosomes) with a 2n gamete (2 sets of chromosomes) for it to be 6x and this rose inherited the ability to generate 4n pollen.
Perhaps Joan would be willing to share this clone with others. My plant of it is getting large and can share it if she is willing for it to be shared. Perhaps it can be used in crosses with diploids to get back down to the tetraploid level just like with using 6x R. acicularis. I don’t know if it would be better or not than R. acicularis, but the only way we can know is to try. It has been a very disease resistant clone.
David, is this the rose Joan found in Idaho? I have the triploid pomifera and one other plant you sent me that I’ve lost the documentation for. Is this the hex woodsii?
Whatever it is, it’s very vigrous and didn’t flower for me, but neither did pomifera.
If they won’t flower in my climate they are pretty much useless here as you can imagine.
We did have a longer colder Winter than usual and still I have nothing unfortunately.
Hi Robert, Hopefully the R. pomifera and other one will flower next year. They often take a few years to get large enough in my climate to flower. The rose I sent from Joan was an op R. stellata mirifica seedling that is 4x.
Having grown up in Fairbanks, AK, we had I presume, R. acicularis as the only wild rose that grew in that area. Is there a source for this rose? I would like to try it for sentimental reasons.
Thanks David. I thought I remember you telling me that.
Phenotypically I can’t get it into my head this rose derives from Hulthemia.
As it derives from seed parent I guess there can be no doubt?
Did you tell me you thought the pollen parent might derive from something canina?
I’ll try to be patient. I am unfortunately short of space.
That woodsii sounds interesting.
“Phenotypically I can’t get it into my head this rose derives from Hulthemia”
Sorry, I MEANT myrifica!
That R.woodsii x R.acicularis cross sounds promising. You
My Nipponensis seeds came from the Arnold Arborium. One seedling appears to be tetraploid, see:
A cross of the possible tetraploid one with Peter Harris’s tetraploid R-15 gave a lot of seeds.
One of the seedlings bloomed for the first time last season:
I have a number of others from the same cross that have not yet bloomed. Plus, I sent seeds from this cross to others (Jadae’s comments are given earlier in this thread).
Jadae, any bloom yet? If so what color are the blooms?
Mine came from The Arnold too Mel but it was lighter pink.
Henry, it’s buds are swelling and Im waiting for it to burst any week now.
They are showing color on the buds now. They look electric pink like Fame! only a few shades lighter. I will take pics when they are fully open.
David, you (and anyone else I’ve shared it with) are welcome to share starts of the hexaploid R. woodsii. I collected it near Yakima Washington. Just be warned–it suckers!
They bloomed yesterday but I forgot to recharge my batteries. Theyre single, large (for a species type), wide-petaled, species magenta with a mauve wash. the blloms reminded me of Geranium ‘Orbit Violet’. The pollen and reporctive parts are highly similar to Rosa rogusa-- white, powder-like and flat. This didnt suprise me because the species Henry used was most likely the rugosa subspecies version of acicularis. Knowing this, I already knew it would self itself asap!I didnt want to waste the blooms to bees so I collected and froze the pollen, and put a mixture of Golden Wings/Baby Love/Rabble Rouser/Hot Cocoa pollen on it (that’s all I could find…it’s still early here). I was kind of bummed at first. I was hoping for yellow. But then it occured to me that the majority of my planned crosses for it involved mauves, so I was happy.