This article was scanned and distributed by Henry Kuska.

American Rose Annual 1946, p 51, 52
Progress in Breeding Hardy Roses
ISABELLA PRESTON
Division of Horticulture Central Experimental Farm, Ottawa, Canada

An article entitled "Central Canadian Rose Breeding" in the 1940 American Rose Annual gives an account of the work done at the Central Experimental Farm, Ottawa. It may be interesting to some of the members to hear how the plants have behaved in the last five years. Unfortunately, they have been rather neglected owing to wartime conditions but some of them have proved their worth as hardy shrubs. It is not generally appreciated how useful rose species and species hybrids could be in a shrubbery border. Few plants are more beautiful than a well grown rose plant covered with single flowers and later, in many cases, with bright red hips to add to the autumn picture. Furthermore, the great variety in foliage effects must not be overlooked.

Rosa rubrifolia HYBRIDS

The original plant of 'Carmenetta' (R. rubrifolia X R. rugosa) grew into a large bush which was very effective with its clusters of bright red flowers and its purplish green foliage but in recent years it has been attacked by a virus disease and has had to be destroyed. A grafted plant seems to be free up to the present and two sister seedlings also appear to be healthy.

Algonquin, an open pollinated seedling of a rubrifolia X rugosa hybrid, has made a bush ten feet tall and eight feet wide but it is very different in appearance to 'Carmenetta'. The foliage is dark green with faint purplish shadings and is large and leathery. The single flowers are Rhodamine Purple with white centers and are almost three inches across. They grow in large clusters and the plant is very showy for two or three weeks in June. The large bottle-shaped fruits are very handsome and in most years are borne in great profusion. [Henry Kuska note: this shows that not only can one get to the next generation, but the next generation also is fertile - sets hips].

Mohawk is of similar descent (R. rubrifolia X R. rugosa) but is a dwarf shrub about three feet tall although the bush is nearly twenty years old. The dull green foliage is small and leathery and the single flowers, rather brighter in color than Aster Purple, have white centers. It makes an attractive bush and flowers for two weeks in June.

Micmac is descended from the rubrifolia-rugosa cross also but is quite different from the two mentioned above. The plant sends up stems about six feet tall but it does not make a solid bush. The texture of the leaves shows plainly their rugosa parentage but the green is so thickly overlaid with reddish purple that the effect is much the same as that of other purple leaved shrubs. The single flowers are borne in clusters and are white with an occasional streak of rose. If the right conditions of growth and a suitable rootstock could be found for this variety, it would be a valuable plant for the shrubbery border..."

In the 1940 American Rose Annual, pages 91 and 92, Isabella Preston wrote:

"Rosa rubrifolia is a very hardy species, and was therefore used as a parent, as well as for its colored foliage. In 1920 it was successfully crossed with a form of R. rugosa. The hybrid was called R. X rubrosa, and the best of the six seedlings was named 'Carmenetta'. The foliage and flowers are intermediate between the parents, but it grows into a larger bush than either. It has been described in a former Annual [Henry Kuska note: I could not find an earlier description; there is one in the same annual (1940) in an article by Percy H. Wright.]. Many seedlings were raised from the reciprocal cross but as all had green leaves, none was considered worthy of naming [Henry Kuska note: the reciprocal cross utilized the 7 chromosome pollen of R. rubrifolia to form a normal rugosa X rubrifolia diploid hybrid — which in itself may be useful for further rugosa hybrid breeding]. Open fertilized seeds were sown, and a number of seedlings raised, a few of which have been named 'Algonquin' (R.28.13.02) grows five to six feet tall. The foliage is large, yellow-green. Flowers are large, single, rhodamine-purple, shading to white in the center, in clusters of one to three. Calyx limb is long and widens towards the tip. Hips are bottle-shaped and attractive.

Mohawk (R.26.18.04) is a dwarf plant about two feet tall. The leaves are small and the single flowers are rather brighter than aster purple. No seed-pods are formed.

Micmac is evidently descended from R. X rubrosa, although its pedigree has been lost. The foliage is rugose in texture but red-purple in color, which does not seem to change all summer. Its flowers are white, with an occasional rose streak on some of the petals. It sets seed, but the hips are not conspicuous. The old wood of this plant frequently dies out.


Henry Kuska note, 25 Oct 1999:

The R. rubrifolia "unbalanced polyploid" behavior of having only 7 chromosomes in its pollen apparently breaks down after forming a hybrid so the hybrids should be useful with other tetraploids.

Perhaps an explanation of what "should" happen in further crosses is in order. If one uses the 'Carmenetta' X R. rugosa cross as either the pollen or egg supplier with a hybrid tea, one does not simply pass 3/4 R. rubrifolia genes and 1/4 R. rugosa genes to the hybrid tea. Instead, one will get many seedlings that will look like they were crosses with a pure R. rubrifolia, a few seedlings that will look like they were crossed with a 50-50 rubrifolia-rugosa hybrid, and possibly many others with mainly R. rubrifolia (but a little R. rugosa) character. As an example of this behavior I will quote the following written by David Austin on page 28 in David Austin's English Roses, Little, Brown, and Company, 1993:

"The third line we pursued was by way of the Rugosa hybrid 'Conrad Ferdinand Meyer.' At first we harbored no great hopes of success, for we feared that the resulting seedlings from a cross with this excessively vigorous hybrid would be altogether too gross in character. 'Conrad Ferdinand Meyer' was itself a cross between the very popular and beautiful Climbing Noisette Rose 'Gloire de Dijon,' and an unknown Rugosa hybrid. It also had one of the most powerful and delicious fragrances. As before, we crossed with some of our better English Rose in particular 'Chaucer,' and had one of those pieces of luck that sometimes turn up in rose breeding. Some of the seedlings from this cross were of typical rugosa appearance, while others bore absolutely no resemblance to a Rugosa Rose. It seemed that some of our hybrids had taken the genes only from the 'Gloire de Dijon' half of 'Conrad Ferdinand Meyer,' while others had inherited those from the Rugosa side. What we had in many instances were in effect hybrids of 'Gloire de Dijon'."

Preston (1922)