R. davidii elongata

Kim’s seedling involving Pretty Lady (a descendant) has got me thinking about this species again, which figures in Baby Love’s lineage as well.

“Like R. davidii, with less blooms, but strikingly large fruit” suggests that perhaps it is just a more fertile form of the species?

Len Scrivens obviously likes it. Have other’s grown and used it? Is it disease-free? Any thoughts on best classes to cross it with to maintain (not dilute) its best attributes?

Thanks

Okay, just to keep it from getting buried completely… Has no one obtained/worked with it then?

Duh…

Tom had crossed it with other species and Simon in Australia was using it, too… I need to remember to use the search tool… I’ve apparently asked about this before. (Sorry)

So… ummm… Any updates?

Phil I am working with R. davidii, the seeds are huge , which may prove to be a bit hard in the germination. (V Petersen) produced Fenja which almost looks R. macrophylla like , both in foliage and bloom. The health of my R. davidii is pretty good here.

Thanks, Warren. “Pretty good” is a little less stellar of an appraisal than I was hoping for. I was wondering if it was the contributor to some really good health in some of its descendants. But I’m guessing mildew might be one of its stronger resistances, and I gather that, like me, Warren, mildew is not something you really suffer from.

(Fenja is pretty cool looking. I really want to play with some of the Pimpinellifoliae. Don’t currently have any.)

Do folks suppose it contributes horizontal resistance to its offspring? Or am I just barking up the wrong rosebush, so to speak.

Thanks

Hi Philip,

Sorry I’ve been out of touch for a little while, so have missed your question until now.

The davidii I have is from ForestFarm nursery and if I’m remembering correctly wasn’t labeled as being elongata.

Here’s [my davidii from ForestFarm]

So far, all I’ve done with it is:

  1. davidii X virginiana - which, although should be carrying a great assortment of disease resistance genes, is still just a suckering, once-blooming, nearly sterile, waist high shrub. It finally bloomed pretty heavily last year but only set one single solitary open-pollinated seed. I also tried fedtschenkoana pollen on it but that was a bust.

[davidii x virginiana]

[davidii and hybrid]

[lone seed from hybrid]

  1. rugosa X davidii - surprisingly fertile for what I’m guessing should be a triploid. It also occassionally sends out some late season blooms. I really like the GLOWY-dark-fuschia color of the bloom. I have to wonder if maybe it’s glowy because of rosafluene, a fluorescent pigment that Don mentioned in an earlier thread. It’s supposed to fluoresce light of the same wavelength as the normal reflected color of cyanidin.[past discussion of rosafluene]

[rugosa x davidii rebloom shoot]

[rugosa x davidii fall color]

Shucks, I can’t believe I never got a good picture of the actual blooms! Very much like rugosa but a little smaller and darker maybe, and with that glow.

  1. davidii X fedtschenkoana - crossing my fingers these will be germinating in the next few weeks. The cross took very well and made fatter than usual hips. Looked like davidii was VERY receptive of fedtschenkoana pollen. I hope it wasn’t a hollow promise. :0)

My Rosa davidii is finally getting to a decent size again after having been moved a couple years ago. It’s never been species that has “knocked my socks off”, but I can’t think of any specific disease issues it suffers much from. Maybe I should start appreciating it more.

Tom

I hadn’t thought about it, but R.d. is in the Cinnamomae. I guess it shouldn’t come as a surprise to me then that you are having luck with other members of the Cinnamomae.

I am quite surprised that the Rugosa cross F1 is recurrent. That’s pretty intriguing. I hope the Fedt. cross will be as well.

Thanks, Tom. Your work always fascinates me. I’d love to see what happens when some moderns get thrown into your mixes.

Hi Philip,

Thanks for those kind words. I’m always glad to hear that somebody’s getting some enjoyment outta seeing my rose stuff. I get pretty excited about some of them myself but it’s even more fun when other people share in the excitement.

As for that rugosa x davidii hybrid, it might be a stretch calling it recurrent. It has made a late blooming branch or two for the past two years, but it’s not anything like a modern rose or a China - not even as recurrent as my multiflora x rugosa, that reliably fall blooms at the tips of new canes. I have wondered though, if I tried propagating one of those late branches of the rugosa x davidii, if maybe I could select out a more recurrent form. You see, the “bush” is really a tangle of siblings that I didn’t get around to planting separately. So it’s quite possible that there’s one particular seedling in that group that’s responsible for those late blooms. I’d sure like to find that out.

Tom

I don’t recall seeing your multilfora rugosa before.

I’m guessing the multiflora itself might have been a hybrid? That baby will be a nice plant to work with, particularly if you can introduce any color saturation into future generations. Really, your work is probably creating lots of interesting foundation plants for new disease-resistant lines.

Thanks for sharing.

I hafta get my joy vicariously, and I appreciate your work! Life has gotten in the way of my playing in the pollen these last several years, and I really don’t feel I can afford to harbor a ton of species roses. (There aren’t too many that really warrant the realty in central TX! If it blooms only once in our 300+ day growing season, needs lots of irrigation, or other life support… I have to be selective.)

Thanks again.

Hi Philip,

The multiflora I used was a wild/naturalized seedling that I picked out of the local population. I don’t think it was a direct first generation hybrid with a non-multiflora, but it did have a few traits that may have been introgressed from other roses.

It was double-flowered (20-30 petals) and had slightly shorter stigma column than typical multiflora. The bloom season was slightly later than the surrounding multifloras, which is what made it stand out to me in the first place. Foliage, growth habit, and thorns were all very much typical for multiflora. I’m guessing that introgression from other roses might be going on all the time into our local multiflora population because aside from this variant, it’s not unusual to find pink petalled and semi-double types too.

My hope is to eventually get this hybrid converted into an amphidiploid and then I could have some REAL fun.

Thanks again for sharing in my excitement about these roses.

Tom