The American Rose Magazine 5(7): 140-141 (Jan-Feb 1944)
The Most Interesting Rose in the World

Percy H. Wright,
Moose Range, Sask., Canada

To me the most interesting rose in the world is the old briar, Harison's Yellow. Is it a Spinosissima, or a hybrid? Where did it get its yellow color? Where did it get its hardiness and freedom from diseases? Why does it vary so in proportion of seeds set? Why are its seeds so hard to germinate?

Harison's Yellow and Persian Yellow are about the only sources of yellow color available to the breeder of hardy roses, and the pollen of Persian Yellow is so rare and so imperfect that the number of hybrids which it has fathered can be counted upon the lingers of one hand. Then, when a descendant is secured, it will be either sterile, as is the Rosa rugosa X Persian Yellow, Agnes, or will transmit susceptibility to blackspot, as did the "grandpere" of all the Pernetianas, Soleil d'Or. Harison's Yellow would be a much more promising parent of yellow roses. Its extremely active and abundant pollen has been found acceptable to almost any rose. The fairly deep yellow pigmentation and other good plant characters would also make it desirable.

However, in my experience at least, Harison's Yellow does not often give a very large part of its yellowness to its offspring. When R. Macouni was pollinated with it, a number of new varieties were produced, all single except one, and the color was either white at the start or a pale bicolor that soon faded to white. Neither the pink of our native wild rose nor the yellow of Harison's Yellow was sufficient to make much impression upon the flower color of the hybrids, except perhaps for a few hours after opening. I also put pollen of Harison's Yellow upon the stigmas of R. spinosissima var. altaica, and obtained one single, intermediate in color between the parents, and two semi-doubles. While both had larger flowers than Harison's Yellow, the color was pale. To be sure, the yellow was not absent, but it was concentrated at the base of the petals where it was scarcely seen.

Other descendants of this rose enigma are Orinda, originated by Miss Isabella Preston at Ottawa, and Harison's Orange, Harison's Lemon, and Harison's Profuse, developed by Stephen F. Hamblin, of Lexington, Mass. Of these the first three are paler editions of their mother parent, and the fourth is white with a faint blush of pink on first opening. The first three were undoubtedly pollinated by ordinary Scotch roses, and the fourth probably by some narrow-leaved species that is hardier than the Scotch roses and hardier than Harison's Yellow itself. Here, in the far north of Saskatchewan, Harison's Profuse and Ottawa's Huron (R. spinosissima X R. cinnamomea) are the only hardy double white roses I know, and of these two Harison's Profuse is much superior. In fact, it is the feature of my rose garden.

Harison's Yellow was introduced before
Persian Yellow reached England.

One of the parents of Harison's Yellow is perhaps that old rose which should get a more definite name, Double Yellow Scotch. But this rose seems to pass on to its children even less yellow than Harison's variety. Hence it is difficult to believe that the other parent was not also a yellow rose. One thinks at once of Persian Yellow, but I for one am not at all convinced that Persian Yellow is a parent. The pollen of Harison's is far too viable and active, to suggest such a parentage. It is also too fertile as a seed parent whenever congenial pollen is present. There are distinct differences in plant characters between Harison's and Persian Yellow such as leaf color (Persian a very pale green, Harison's very dark), vesture, and resistance to disease. Of course it is possible that one of the Foetidas other than Persian Yellow, and probably other than Austrian Copper, may have been the second parent. A single, fertile variety of R. foetida pollinated by Double Yellow Scotch might conceivably have given rise to Harison's variety.

Harison's Yellow is really more arctic in its adaptation than either of these. Not only is it hardier, but in autumn its bark colors up sooner, and to a deeper tone. It also drops its leaves sooner. On the other hand, it seems incredible that it could be a pure Spinosissima, but not on account of its petal color. A species that could produce a Double Yellow Scotch might possibly produce a rose as yellow as Harison's. Harison's Yellow is very different in habit; it is more erect and not nearly so finely branched at the base. Most important of all, the number of leaflets is different. Again, its hips are not black, as in Scotch roses, but brown, intermediate between black and red.

I have another descendant of Harison's Yellow, the result of putting its pollen on either R. blanda or R. laxa Retz. (I have lost track). The seedling has inherited the bark color of Harison's Yellow with still more intensity, so that the bark is red, not only in autumn and winter, but through the summer while growing most rapidly. It strongly suggests R. xanthina, for it has the same leaflet number, which is greater than either parent. I would suspect R. xanthina of being the other parent of Harison's Yellow except for the fact that it is less hardy here than even R. spinosissima. Does there exist a strain of R. xanthina which is yellower and hardier than the type commonly grown in American gardens, and as hardy or hardier than Harison's Yellow? If so, I would like to get it to use in breeding work.

Allard (1900) also raised seedlings from 'Harison's Yellow'. One was as deeply colored as Rosa foetida/