"Did I write you earlier about the R. acicularis from Fairbanks, Alaska. In case I didn't, I'll tell you the bare facts now. I hoped for the octaploid strain of this species, and asked a correspendant to send me two plants. I had one of these analyzed for chromosome number by the cytologist at the Canada Agriculture Research station here. It turned out to be a seplaploid, with 49 chromosomes. Doubtless there is an area where the octaploid and hexaploid forms overlap, and this plant came from that overlap area.
Robert Erskine told me that he got a fertile hybrid between a tetraploid rose and a local strain of acicularis, which would give a hexaploid. If his local strain was hexaploid, the hybrid would be pentaploid, and almost sterile. This would suggest that the octaploid descends into Alberta as far as Carlos at least. Interesting, isn't it?

Personal Correspondence - Percy Wright to Walter Schowalter - January 18, 1971

"I have come to believe that when a rose contains genes of too many species, they agree so poorly that blooming is inhibited. This does not mean that genes cannot be mixed from any source, but that when a hybrid is produced between two species, a second, third, or fourth generation must be raised before it can be used to cross with a third species. The HT's of course, have been inbred so long that their genes (that is, the genes of the fertile ones) have had a chance to "settle down"; so that they can act as species. In any event, I lost year in my rose breeding program by having to find this out by experience."

Personal correspondence Percy Wright to Walter Schowalter September 15, 1969

From the American Rose Annual:
The Yellow Rose of Texas
Percy H. Wright
Saskatoon, Saskatchewan, Canada

The little verses in a recent issue of the "American Rose" magazine on the identity of "The Yellow Rose of Texas" as simply the old-time hardy 'Harison's Yellow' struck a responsive chord when I read it. Although Saskatchewan is a long way from Texas, it happens that I had heard before of "The Yellow Rose of Texas".

The late Dr. F.L. Skinner of Dropmore, Manitoba, whom no private horticulturist on this continent has a more renowned name, once sent me pollen of "The Yellow Rose of Texas" for use in rose breeding. He described the flower as identical to that of 'Persian Yellow', but the plant as different, more vigorous, growing up to nine feet instead of five feet or so that we are all accustomed to seeing 'Persian Yellow' reach.

It turned out that the rose he had under the name which has given me the title of my essay, was indeed 'Persian Yellow', and that the increased height and vigor are due to its being on its own roots. How many people, rosarians included, are aware that 'Persian Yellow' will indeed grow to nine or ten feet when on its own roots? And yet, the species to which it belongs, Rosa foetida, is described as attaining ten feet in the "Rosa" section of that encyclopedia of roses, Modern Roses 7.

'Persian Yellow', in the section on varieties of roses, is given the name foetida persiana, which would lead one to conclude that 'Persian Yellow' itself would attain the same height—unless by some rare chance it might be a dwarf selection of the typical species. It isn't; I can myself attest to that, for I have seen 'Persian Yellow' plants all of nine feet high, right here in Saskatoon, Saskatchewan, where, on account of our northerly location, one would expect somewhat less height than in the more lush country farther south. Many rose cultivars have their vigor increased by being budded on multiflora or some other understock, but 'Persian Yellow' is the exception. Its natural vigor is very considerably reduced by having multiflora as its rootstock.

In writing the foregoing, I am not disputing the identification of "The Yellow Rose of Texas" as 'Harison's Yellow'.

"My aim in breedling new roses for the prairie provinces have changed so radically in the past few years that I am moved to explain, and in process of doing so, to give a short account of my efforts in this line since I made my first cross, back in 1931.
The cross involved putting pollen of one of our three native rose species, Rosa Macounii, on the emasculated flowers of our well known Rugosa hybrid Hansa. among the seedlings resulting was an attractive, once-blooming variety that I named Mary L. Evans. This initial success had the consequence of arousing my interest in rose breeding, an interest which has been maintained to the present day (June 21, 1976). In this interim I have raised many thousands of hybrid rose seedlings.
For years I thought of the problem of the rose breeder as chiefly one of combining three qualities, hardiness, brilliant and well-formed flowers, and everblooming. It was not until about the year 1965 when I realized that the serious plague of orange-rust on rose leaves, stems, and hips should preferably be met by originating new varieties immune to it.
All our native roses are subject to the rust, especially the dwarfest of the three, Rosa Suffulta, the species which is such a weed in the grainfields of the grasslands area. It is a pity to cut out this most interesting little native, so persistent, so drought-tolerant, and if properly pruned, so willing to bloom in the fall. Rosa rugosa is also subject to rust. Where, then, shall we look for the genes for immunity?
It happens that there are three roses, all exotics, which offer very considerable resistance to rust. They are Scotch rose so called, Rosa Spinosissima, with its variant or subspecies Rosa Altaica, from the Altai Mountains of Central Asia; Rosa laxa, from the plains just east of the Ural Mountains of Central Asia; and the Ross Rambler from the Himalayan Mountains north of India. All three are of remarkable hardiness, but only the last-named is everblooming. With time, we can get everblooming from the other two, but we should be able to get it more quickly from the Ross rose."

Paper in Personal Correspondence from Percy Wright to Walter Schowalter June 21, 1976