R. acicularis question for Henry K.

Dr. Kuska,

I was wondering about the ploidy of the R. acicularis used in your seedling ((Calocarpa X R. nutkana) X (R. acicularis X O.P.)). I know R. acicularis has various ploidy levels. I noticed on your website that you mention both R. acicularis and R. acicularis nipponensis, which is the diploid R. acicularis.

I ask because you were kind enough to furnish open pollinated seeds from the above to me this spring. I’ve had numerous germinations, and the physical appearance of the seedlings varies widely. Most are very slender in all their parts and look like typical diploid seedlings, while a few are much stouter.

Mark Wesson

I originally had the diploid form, but then it appeared that at least one of the open pollinated seedlings of it was either a cross with something else or the tetraploid form, see:


The mother of the seed that I sent you was my number 413, it had a pollen diameter of 27.8 +/- 3.3, so it was probably a diploid see:

Link: spreadsheets.google.com/ccc?key=0Au5KXZAJsCdkcHhIaFR3N3lsZzctWkxaRWZKcjRlRXc&hl=en

How well does R. acicularis pass on it hardiness? What other traits does it tend to pass along?

Dr. Kuska, are all the pollen data you have taken on this spreadsheet?

Henry is this the same R. Acicularis you used in the cross I got from you I believe was two years ago.

R. Acicularis X (Hansa X OP) X OP



Mark, a picture of (Calocarpa X Nutkana) X (acicularis X OP) is at:


Adam Eckstein, regarding hardiness: unfortunately northern Ohio is not the place to test for “true” hardiness that would apply to Canada, northern Wisconsin, Minnesota, etc conditions. Here, even Rugelda X R15 is completely hardy.

Sorry, I cannot say much about what other traits it passes along. The F1 do not show disease but most (almost all) of the roses in my “natural” garden are in equilibrium with their surroundings. With around 1000 roses I have not taken the time to record which spread by runners, average height, width, number of leaves, shape of leaves, etc.

Pictures of other acicularis crosses are at:














Plus, see Hansa crosses later in this post.

Don Holeman, the raw data are entered into a bound notebook, when I find time, the data are averaged, stastically analyzed, and entered into my master notebook. At some future “free” time I enter them into the on line spreadsheet. i.e. I do not know how “up to date” it is. Since this is off season, I cannot even tell you where my notebooks are.

Patrick, it probably is, but I cannot say for sure as I had a number of germinations from the original seeds provided to me from the Arnold Arboretum (see page 97 *Rosa acicularis var. nipponensis at http://arnoldia.arboretum.harvard.edu/pdf/articles/1050.pdf ).

(R. Acicularis X OP) X (Hansa X OP) pictures are at:









AND the reverse cross is pictured at:



Thank you Dr. Kuska.


The R. a. nipponensis hybrid (R. a. n x R15) that I raised from Henry definitely creates a concentrated mass of suckers. The architecture and size mimics Rosa virginiana exactly. I am assuming it is tetraploid, but it could also be diploid. I highly doubt it is triploid. Whatever it is, it makes a nice garden backdrop for its nearly-feral lineage. Ive often wondered if it is 1/8th rugosa, but I have no clue really.

Thank you so much Henry!!!


Another surprise from these seedlings. One of them has a flower bud at just a few months of age. I didn’t expect that. Perhaps in this case open pollination was not self pollination.


I know several of you received seeds from this cross from Dr. Kuska. I was wondering if you’ve had any success in breeding with it. I still have a single seedling from this cross, and I’ve tried it in various combinations the last few years as both pollen parent and seed parent. I haven’t had any luck except with crosses with r. virginiana (last year) and r. arkansana (this year) and one maybe cross with Carefree Beauty from last year (all as seed parent). It’s been surprisingly healthy, so I’d like to find something more modern to use it with. Anyone had any luck?


The form of accicularis I have native to my area is very prone to black spot. The woodsii also native here (diploid) is much more resistant but is plagued by Rust. I use it as a stud to for greater hardyness than R. rugosa. It is the most delightful of and delicate simple unobtrusive growth.

I have that cross and have been using it quite successfully in many crosses. I have a repeating offspring from ((Calocarpa X R. nutkana) X (R. acicularis X O.P.)) x Cafe Ole. Very disease resistant, prolific rebloomer, and a good looking but still young plant. I have more than one (I kept about 10 seedlings out of over 100+ that I raised-discarded all the disease prone ones and kept a sampling of all the healthy ones) of the original seedlings (from the seeds from Dr. Kuska) and am not positive about which was the ‘mother’. About half resemble nutkana and the other half resemble acicularis strongly. This past yr I made several crosses of the repeating seedling offspring and will see what pans out. I do have several other offspring with ((Calocarpa X R. nutkana) X (R. acicularis X O.P.)) as the pollen donor, and at least 2 of these are also repeating but I am not sure that they are not selfs-although I do believe that at least one was a successful cross. It is fragrant, double, repeating and has not produced any hips. I do have other offspring one each with r. foliolosa and with Prairie Peace. All seem to have superb disease resistance and vigor. The r. foliolosa and the Prairie Peace crosses both bloomed at one yr and produced hips of which none have germinated yet. I planted out a ((R. wichurana X Pink Drift) X ((Calocarpa X R. nutkana) X (R. acicularis X O.P.)) x Bayses legacy today( I know that I did not get those parentheses correct, it is late!). A lot of the R.wich cross seedlings have been quite small and fragile and we have been having a heat wave here, with very high winds, so some of those have not made it. This one was a bit sturdier so hopefully it will make it. I am keeping it in the shade for a day or so, but do not like to do this at this time of the yr. The ((Calocarpa X R. nutkana) X (R. acicularis X O.P.)) does not seem to mind the heat, but it does not like the extended drought to much. Of the ten seedlings that I kept of the original germinations, only one does not produce suckers, and this one is one of the better hip producers. It is one of three that I have been using for most of the crosses I have done. Hopefully this is the some of the type of info you are looking for.

Thanks, Jackie. The one seedling I kept has done surprisingly well in the heat here and has suckered widely. I was hoping to find something more modern that would work with it. It set OP hips easily. When I use it in crosses, the hips that are produced only have a few seeds and germination is poor.