Gymnocarpa Breeding (or lack of)

I’ve been back tracking some old notes. Gymnocarpa was was a rose I looked at briefly. I checked it out again on HMF a few minutes ago. I found it intersting that there are NO decendants.

One of the qualities that I like about this species rose is its shade tolerance. There are several growing on my property in shaded areas. From what I’ve read and experienced, there are realatively few shade tolerant roses.

Would shade tolerant roses be worth persuing or has this been attempted and abandoned for some reason?

Personally, I always thought gymnocarpa or pisocarpa would be good to try and use over woodsii. If I hd the time and space, I would try to cross them onto rugosa, and then onto a diploid dwarf like a R wich. groundcover type.


I have the space and time. Breeding with it would be more of a curiosity at this point. I just found it interesting that there isn’t any lineage listed in HMF. Next Spring might be a good time to splash some pollen around and see what happens. I’m not sure what an ultimate goal would be other than to satisfy an interest in different crosses.


Totally go for it! :slight_smile:

Yes, gymnocarpa is ripe for utilization.

R. gymnocarpa will NOT set seed with foreign pollens, but its pollen went easily onto a variety of seed studs I commonly use. Same experience to be had using R. woodsii and R. pisocarpa. I have R. woodsii seedlings already in progress.

Paul, if you don’t mind me asking, what is your source of woodsii? Are you staying diploid or working it into your tetras?

My R. woodsii is only a tentative ID. It is a plant collected from a frigid, inhospitable peninsula of Ontario, CA many years ago, where it grew happily in either full sun or total shade. It matches descriptions of R. woodsii fendleri, but who really knows…

I have no idea what its ploidy is and am cautious about speculating. These species are variable from location to location, which suggests hybridity to me. I have one in a large container I can have tested using the root tip squash. I can pursue that if you want. I can also supply suckers later this month when it drops the rest of its leaves. Bear in mind that this specimen doesn’t set seed at all, not even OP seed, so it is a pollen donor only, IMO.


Yeah, the species in Oregon often look like a mixed bag to me. Add in the mix that roses like Rosa canina have naturalized here, too, and it gets confusing very quickly.

Thanks for the offer Paul. I’ve got way too many irons in the fire as it is.

I’ve got to resist temptation! =)

I am one of those that doesn’t believe in the purity of species no matter what the source.

Personally, I’m part Manta Ray =)

kidding, lol :slight_smile:

Yeah, nature isnt very picky, is it? lol

Is there suggestion that on some level roses in general might be less than virtuous?

I confess, the thought, has crossed my mind.

“Is there suggestion that on some level roses in general might be less than virtuous?”

Yup lol.

Yes, under cultivation, many things are possible. But in the wild, there can be very real barriers to hybridity. It is an over-generalization to suggest that the lack of purity of species is true everywhere or of all species. Some locations have very isolated populations of only a single species rose and very sparse or non-existent populations of cultivated roses. Differences in timing of flowering also prevent some species from cross-pollinating. Cross-species fertility barriers exist. I don’t question that certain locations, like Central Oregon or the northern Plains or the Mid-Atlantic States mark the intersections of several species, where they may intergrade. It’s an issue of location and climate.

So while hybridity is a constant in some locations, such as those where several species share a single habitat and bloom at the same time, it is not as universal as you suggest. Even where two species share a habitat in terms of being located within the same county, they may have only a rare opportunity to hybridize, say at the very beginning of the bloom of one and at the very end of the bloom of the other.

This was brought home to me in the High Sierra, where nighttime temperature are already in the 20’s and it’s probably a USDA Zone 5-6. There is a species rose growing everywhere - - roadside, creekside, in vacant land, in old cemeteries. The only rose species native to the Sierra Valley is Rosa woodsii var. ultramontana. It’s too high and cold for R. californica, too southerly, dry and inland for R. nutkana or anything else, for that matter. Most of the cultivated roses sold up there die because it’s too cold for the commercially available cultivars sold in California budded to California rootstock. So if I see a wild rose, I feel very comfortable identifying it. It’s a widely variable rose, by the way. That how it survived over such a large and challenging geography.