R. arkansana is, in fact, also known as the Prairie Rose and it is native to a large portion of central North America, from the Appalachians to the Rocky Mountains, and north to Canada. This once-yearly bloomer ranges in height from one to three feet, although on the native tall-grass prairie of the Flint Hills I seldom see it above the foot mark. There are 5 heart-shaped petals on this single, medium pink rose, and the center is covered with numerous bright yellow stamens. According to the Kansas Wildflower site, it has roots that may go down more than 20 feet into the prairie subsoil and it is very drought-resistant. The species name, arkansana, refers to the Arkansas River of Colorado, not the State of Arkansas. It is the state flower, however, not of Colorado or Arkansas, but of North Dakota and Iowa. Very confusing, isn't it?
If it has become evident that no individual identity is sacred or private on the Internet, it is even more evident for our plants. I knew that this native rose was one of those used in the breeding of the AgCanada Parkland series roses, but during my search for information about R. arkansana, I found a 1976 article about breeding with R. arkansana written by none other than H. H. Marshall of the Morden Research Station. I've now learned that R. arkansana is a tetraploid, containing 28 chromosomes, and so it is compatible to breed with most of our modern Hybrid Teas and Floribundas, although there are strong interspecies sterility barriers between R. arkansana and cultivated roses and so the F1 generation hybrids are hard to come by. R. arkansana provides its hardiness to the offspring and it lends an extended blooming period due to adaptations that allow it to bloom after grazing or spring prairie fires. It is also tolerant of the dry and moderately alkaline soils of the prairie. To get the initial interspecies crosses, the Canadian program discovered that a few modern roses, such as Floribunda 'Donald Prior', would accept R. arkansana pollen. The AgCanada releases 'Cuthbert Grant' and 'Adelaide Hoodless' were two of the later generation crosses that had 'Assiniboine' (a first generation cross of 'Donald Prior' and R. arkansana) as an ancestor. Now I understand why 'Adelaide Hoodless' is essentially a once-blooming rose with a very long (over 6 weeks of bloom) season. I also have learned that the bright red pigment of 'Adelaide Hoodless' looks a little different from other roses because it carries the pigment "Peonin", absent in most modern hybrids but inherited from R. arkansana.
