It’s been stated that a Floribunda or Rosa beggeriana is the other parent of the Rugosa ‘Schneezwerg’. The former can’t possibly be true, because of the excellent cold hardiness of this cultivar. The latter possibly can, since it could contribute cold hardiness, smaller leaflets than a typical Rugosa, and the very good repeat and late blooming habit of the shrub. However, there is one major problem. One would expect ‘Schneezwerg’ to have globose (and perhaps maroon red colour) hips, but they are obovate, which is unusual in a Rugosa hybrid. Rosa fedtschenkoana can contribute all the characteristics that Rosa beggeriana can if hybridized with Rosa rugosa, but also obovate hips. Of course if Rosa fedtschenkoana was a parent of ‘Schneezwerg’, it would be expected this cultivar would be a triploid, when, in fact, it’s a diploid. But that doesn’t mean it couldn’t have happened. For example, perhaps there are diploid populations of Rosa fedtschenkoana and the pollen came from this source. Anyway, I expect this mystery to be solved at some point in time.
What do you think of a diploid like R. laxa R. / something like ‘Ross Rambler’ being the parent? The R. laxa R. I counted are mostly diploid. I haven’t grown R. fed., but they seem similar from pictures. Maybe R. laxa R. is a diploid form of R. fed. or at least have some close affinity???
David,
In the case of Rosa laxa possibly being the parent, I would expect ‘Schneezwerg’ to be more of a rangy shrub. But it’s possible, of course.
Yes, judging by both species having white flowers and having the same linseed fragrance, plus being located in the same geographical area, it appears there is a very close affinity between Rosa laxa and R. fedtschenkoana.
David, do you need Fedtschenkoana? I brought it with me in the move and it doesn’t appear to be liking it here. There aren’t suckers yet, but if you’re able to bud anything now, I can cut bud wood.
Täckholm (1922) wrote that Almquist regarded the whole “laxa” group as hybrids of beggeriana and cinnamomea. With crosses among these, and backcrosses to the parents, we should expect a range of diploid forms. Some would pass for R. beggeriana, others would approach R. cinnamomea (or davurica). One plant Täckholm examined was a tetraploid.
However, Yang, et al. (2014) found only diploid R. beggeriana and tetraploid R. laxa growing in Xinjiang, China.
Another bit of supporting evidence of hybridization.
Boissier (1888) described R. cinnamomea, then added:
β. > pisiformis> .— Differt foliolis minoribus minute et brevissime dentatis, inflorescentia corymbosâ, floribus minimis magnitudine > R. Beggerianae.> —Toto adspectu inter > R. Beggerianam > et > cinnamomeam > intermedia, ob bracteas latas potius ad ultimam speciem ducenda.
Hab. in Armeniâ Turcicâ (Auch. 1431).
Eandem vidi in herb. cl. Crépin prope Sareptam Rossiae austro-or. ab A. Becker lectam.
It would be a matter of judgement whether to include this pisiformis as a form of R. cinnamomea or to acknowledge it as a probable hybrid derivative.