jbergeson wrote: ↑
Fri Sep 13, 2019 11:18 am
For the record, I don't have a lot of confidence in species labeling. There is so much variation within a species, potential intercrossing, and when a nursery gets involved mistakes happen and inaccuracies are compounded.
Gordon Rowley discussed this problem back in 1951.
"Sometimes it is even possible to suggest, on cytological grounds, the other parent of such aberrant individuals. Five Kew seedlings received as Rosa pendulina
(tetraploid) turned out, surprisingly enough, to be all heptaploid, with somatic counts of 2n=49 (or very nearly so). Examination of the Kew "pendulinas" revealed one that was an octoploid under the name of R. balsamea
, and next to it as its nearest neighbour a hexaploid, R. nutkana
. Perhaps these were the parents of the mysterious heptaploids which, for all their odd ancestry, flower well and seem remarkably fertile."
And I will add that from what I've read on the subject, I have never seen a genuine Rosa rugosa.
The species is supposed to be once-blooming, sometimes with scattered repeat. The blooms should be borne singly, or sometimes in pairs. A dependably reblooming plant with clusters of flowers would not be recognized as R. rugosa
by Thunberg if he happened across it in a garden. In fact, the Rugosas that we now have originated from seeds collected in a Japanese garden. No telling what the other parent(s) might have been.
Also, early sources agree that the leaves of R. rugosa
(as R. ferox
) should be tiny ... like R. wichuraiana
. Leaflets just over 1 inch would be about right.
And somewhere in my notes I have Hurst's comment that American species seem to be more nearly true-breeding than European species. Maybe after the "species" were passed along by seed from garden to garden for a few decades.