Does anyone have any experience with Rosa Cinnamomea Plena? I have a huge 100+ year old patch in Zone 3. They produce no hips, little pollen and sucker like crazy. Their hardiness, petal count and spreading habit are desirable but I have little information regarding their breeding usefulness. Thank you.
Victoria MacPhail reported on the reproductive biology and insect pollen vectors of a number of native and naturalized roses in Canada at the recent International Rose Symposium on Rose Research and Cultivation. She is a graduate student at the University of Guelph. She mentioned that this species rarely ever sets hips.
Sincerely,
David
I have grown R. cinnamomea plena for a number of years. Its good properties have always interested me. The form of its doubleness seems different from that of most other roses. The center organs are like twisted petals, and often appear to have anther-like sectors. In at least one year, these seemed to actually be making pollen. I went through a lot of effort to collect it, and I got some. Unfortunately, it did not make a single seed, even with my most fertile female parents. On the other hand, it did make a few hips that year and a couple other years as well. I collected and planted the seeds.
I ended up with several R. cinnamomea plena open-pollinated seedlings, and two bloomed this year. I have no way of knowing the male parents, but one has a single white flower and I assume that its parent was a white R. spinosissima ‘Altaica’ hybrid that is nearby. The other was just like R. cinnamomea plena itself in plant, flower color, etc., and I assume it is the result of self-pollination. This last seedling was also very double, but with normal inner petals and stamens, so I was able to collect pollen. I used pollen from both this year. Hip set was light, but OK. I haven’t shelled them out yet. You might want to go over your plant every year with extreme care, looking for any hips. It is surprising how many “sterile” plants make the occasional hip. That’s where R. kordesii came from, after all.
Another option is to use the original, single flowered form of R. cinnamomea, but I have never found a source. Finally, some roses are generally believed to be hybrids of R. cinnamomea. Examples include some Gallica roses, including “Empress Josephine.” Also, a rose collected in Siberia and named ‘Dr. Merkley’ has been suggested by some experts to be a R. cinnamomea hybrid. It’s another hard one to come by, although I was able to buy it from Skinner’s Nurseries a few years back. I got a couple of hips from its pollen this year.
1 Like
Thank you so much for your response. I commend you for tedious work of pollen collection of these flowers.
This last weekend I carefully (those awful prickers!) went through the patch and collected 10 hips. My theory is that these hips are from hybrids that over the generations have developed from pollination with a variety of other wild roses and rugosas in the nearby vicinity. Hopefully I will have some germination. It is very encouraging to hear of your seedlings.