Rose Annual, pp. 23-30 (1920)
Rose-Breeding Notes for 1919
DR. W. VAN FLEET
Department of Agriculture, Washington, D. C.
EDITOR'S NOTE.—It is not only the inherent interest of these notes, but their continuity, that gives them unique value. They should be read in connection similar notes by Dr. Van Fleet in the Annuals for 1916, 1917, 1918, and 1919, in order to appreciate their relation to world-progress in rose improvement. A recent comprehensive inquiry addressed to all the important known rose-hybridists has convinced the Editor that Dr. Van Fleet alone is intelligently, persistently, and scientifically adventuring in the development of the different and important Chinese native species from which may arise, in earlier or later succession, the improved hardy garden roses so much needed.
It is no derogation of the efforts of the commercial workers in roses primarily bred for greenhouse growing, nor of the superb work of Captain Thomas toward hardy everblooming climbing roses (fully reported and illustrated in this Annual), to say that Dr. Van Fleet is the present and potential originator of varieties which may truly be called "American" roses.
Attention is directed, in illustration of this article, to Plates III, V, VI, and VII, and to the portrait of this great hybridist, printed as Plate II.
Attention is also directed, in view of Dr. Van Fleet's last paragraph, to the efforts of the American Rose Society, to suitably arrange for the dissemination of the fine new varieties referred to on page 29.
|PLATE III. unnamed Hardy Climbing Rose (Rosa Wichuraiana x Duchess of Wellington). Originated by Dr. W. Van Fleet;
as Photographed in the Editor's Garden.
|PLATE IV. The Chinese Species, Rosa Multibracteata
(Photographed in the Editor's garden
THE past season was far from ideal for rose-breeding. The blooming period was interrupted by long rains, interspersed with heat-waves that made pollination more than ordinarily precarious, and, in addition, the rose-chafer, or beetle, appeared in incredible numbers, destroying foliage and pollinated fruits as well as the flowers of many varieties much desired for breeding. The most trying feature of the season was the surprising amount of damage caused by the seventeen-year locust or cicada, which appeared to specialize on the upright canes of the new Chinese roses for their egg-laying operations, with consequent splitting of the stems, stunting of growth, and causing, in no inconsiderable number of cases, their breaking down and the total loss of hybridized fruits before maturity. This trouble was to a great extent avoided in the later pollinations by selecting blooms on small and low branches less likely to be attacked, but the net result of this invasion was a material loss in the season's work and the total destruction of certain combinations difficult to secure, which, however, we hope to again effect in coming years. The seventeen-year locust pest is not again due in this locality until 1936. The other troubles we always have with us, and full precautions will be taken to minimize their effects in future work.
|*See Plate IV, facing page 20 for Rosa multibracteata.|
Notwithstanding the seasonal difficulties, a very considerable number of pollinations among the new or little-used species and rarer varieties have yielded good seeds and may favorably be heard of in coming years. Best results were had with Rosa Gentiliana, R. bella, R. Helenae, R. sertata, R. Jackii, R. omeiensis, R. banksiopsis, R. saturata, R. Sweginzowii, R. mulitflora cathayensis, R. filipes, and R. multibracteata,* all from north or central China, though quite a number of other varieties from Asia and western North America matured hybridized fruits or furnished a few successful pollinations with other species or varieties. In all these crossings, habit of plant, quality and season of bloom, and relative hardiness, or disease-resistance, were taken into account in planning the matings, and in most cases a variety with superior blooms for its class was used as seed or pollen parent. It seems reasonable to expect useful results from this basic work in the way of laying foundations of future valuable hardy rose strains for America.
Of the new species mentioned, Rosa Gentiliana and R. Helenae appear to hold greatest promise. Rosa Gentiliana first blossomed at Bell Experiment Plot, and possibly in the United States, in 1918, and more profusely the past spring. It may be claimed without qualification to be the most attractive wild climbing rose with white flowers thus far introduced to cultivation. The plant is far from hardy in the latitude of Washington, and will scarcely find really congenial climatic conditions north of the Carolinas, but has endured three winters at Bell with varying loss of branches. It is a strong grower during the warm months, making canes twelve to eighteen feet high in a remarkably short time. It is not a trailer, and should be given support on a south wall or other well-protected situation in cold climates if its full characteristics are to be brought out. In the milder southern states it should succeed anywhere that its rambling growth can be supported, and may even naturalize itself and become a local nuisance, as the Cherokee and Macartney roses have done along the irrigating ditches and levees of Louisiana and Texas. The foliage is large, abundant, and glossy, with a peculiar reddish reflex to the under surface of the leaflets, and the fair-sized snow-white blooms are borne in spring in such astonishing abundance as to give the plants the appearance of a veritable snowdrift. The individual flowers greatly resemble in form, size, and purity the blooms of the large mock orange, Philadeiphus grandiflorus, or, more correctly, P. inodorus, and have, in addition, a pleasing fragrance that is lacking in that scentless shrub. They are thickly placed in large clusters all along the canes and are quite lasting in their snowdrift effect, as the stamens are few and small and do not disfigure the older blooms as do those of the white Wichuraiana and Multiflora varieties. A good crop of deep red hips follow and retain their bright color well through the winter. Whether this fine species can be altered for the better by breeding into it greater hardiness is a problem for the future.
|PLATE V. Rosa Moyesii, the Deep Red Chinese Native Species||PLATE
VI. New Hybrid Rose, "W. M. No. 5"
(unnamed Wichuraiana-Setigera Hybrid X R. Moyesii). Originated by Dr. W. Van Fleet
Rosa Helenae is a climbing species of the Musk rose group, but much hardier than R. Gentiliana, as it thrives vigorously as far north as the Arnold Arboretum in Boston. The white blooms are produced in June almost as freely as those of R. Gentiliana, but are less pure in color-effect, as the abundant yellow anthers in fading soon mar the clusters. It is, however, a most desirable wild rose, fitted for culture over a wide area, and appears to cross almost as readily with other species and varieties as R. Wichuraiana. One hybrid, R. Helenae pollinated with the Tea rose, Isabella Sprunt, has bloomed, giving a pretty, double white bloom with yellow base, in good-sized clusters. The plant is a strong, healthy rambler, quite comparable to Thalia; but something more striking in appearance than this newcomer will be needed before R. Helenae hybrids take a conspicuous place on the map.
Of the newer species, R. bella and R. multibracteata are most enticing, the former for its dwarf habit and profusion of bright cherry-red blooms, and the latter for its fine, distinct foliage and graceful sprays of late-opening pink flowers. Both are shy seeders at Bell and reluctant to cross with other roses, but have matured some hybrid seeds. The latter species is illustrated in this issue of the Annual, facing page 20.
|*See Plate, V, opposite, photographed from a plant growing in the Editor's garden.|
Of the more familiar species, R. Moyesii must take first place on account of the superb deep red coloring of its blooms. It has been termed, in England, where it was first cultivated, "an epoch-making rose," and in our view it well deserves the title, as it is the most striking in color-effect of the Oriental wild roses that has come to notice. It has flowered at Bell four seasons, and each year deepens the impression of its great possibilities. The few direct seedlings and hybrids of R. Moyesii that flowered the past summer have shown no charms greater than the type, except in the fine cinnamon-red color of the winter canes in one variety; but the pollen hybrids of R. Moyesii with R. arkansana, R. canina, R. Engelmannii, R. Fendleri, R. Malyi, R. rugosa, and R. Wichuraiana open new visions of beauty in garden roses of the more robust types. Of these the crosses with R. canina, R. Engelmannii, and R. Wichuraiana are the most alluring at the present outlook, though further developments may change this rating. Rosa Wichuraiana X R. Moyesii was described in the 1919 Rose Annual under the tentative designation of "W. M. 5." Another season of bloom confirms our estimate of the value of this novelty. There is little indication of R. Moyesii in the plant except in the large black-crimson blooms with deep red filaments, borne in the greatest profusion in spring and again to a considerable extent in autumn, followed by large and particularly glossy red fruits. It is very healthy and hardy, and should make an exceptionally attractive pillar rose*.
The hybrids of R. canina and R. Moyesii in their second year show great promise, having a sturdy, arching habit, handsome foliage intermediate in form between the parents, and large, fiery crimson, wide-opened flowers in open sprays near the tips of the branches. The anthers and stamens are golden yellow, relieving the blooms from the somber effect seen in the extreme forms of R. Moyesii, such as the variety sent out in England under the name of R. Fargesii, in which the filaments are maroon and the anthers dull red-brown. The flowers of the R. canina-R. Moyesii blends reflect more light and give a far more brilliant effect than those of the typical R. Moyesii, and may in older plants be more freely produced.
The finest of all the R. Moyesii hybrids, from present appearance, are the R. Engelmannii crosses. Five excellent varieties, differing in brilliancy of tint and habit of plant, have appeared among the numerous seedlings under way. All were profuse bloomers at two years from germination, bearing flowers of the brightest reds imaginable, with conspicuous yellow stamens, the bloom coming solitary or in pairs in short twigs over the entire plant. The flowers are large, well-shaped, and lasting, giving an especially glowing effect against the deep bluish green foliage, which is in form more like that of R. Moyesii than that of the seed parent. The succeeding fruits are pear-shaped and remarkably large, becoming bright orange-red in maturity. These varieties will probably form strong clumps of canes five or more feet high in the next year or two, and, in common with the Dog-Rose hybrids of R. Moyesii, will readily be propagated by layers, which are already produced with freedom.
Rosa Engelmannii is a little-known Rocky Mountain wild rose of neat, erect habit, and bears, in the form under cultivation at Bell, the most cheerful red flowers of any American species. All of the other R. Moyesii hybrids show promise for future development, if not for immediate dissemination. Rosa Moyesii itself is indispensable in any considerable rose collection, and will always center attention when in bloom or fruit. It makes the tallest growth of any non-climbing rose at Bell, the erect canes reaching eight feet in height in a season, but is not especially free in the production of its unique and elegant flowers, and, in addition, is most difficult to propagate, except by grafting on R. canina and R. Manettii stocks, which seems to render it short-lived.
We are trying to extend the hybridizations through the entire range of congenial species and highly developed garden varieties that do not too greatly conflict in habit and coloring. Flowers of R. Moyesii and all hybrids yet developed to the blooming stage are devoid of fragrance, and their charms will likely continue in the lively coloring and graceful forms. Attractive double blooms of the R. Moyesii type are scarcely to be anticipated, but may eventually come to pass.
Rosa Hugonis continues a difficult subject. While fruiting with the greatest freedom, few of the very numerous seeds germinate, whether cross-, self- or chance-pollinated. We have, however, about three hundred seedlings under way, the most desirable from the present outlook being hybrids of R. altaica and R. hispida, both geographical variants of the Scotch rose, R. spinosissima. The ultimate appearance of these newcomers can only be imagined, as few are more than three years old. If their growth continues after the general pattern of R. Hugonis, we may anticipate luxuriant shrubs for hedging and specimen planting, six to eight feet high, in early spring completely wreathed with cream-white to canary yellow flowers nearly four inches across, and so thickly placed as to touch all over the branches, being succeeded by glossy, fern-like foliage, and in August by a profusion of red or black fruits, often of considerable size. A few of the hybrids have blooms of deeper yellow than R. Hugonis, but the larger-flowered varieties run lighter in color, like their pollen parents. There is considerable difference in habit, some having comparatively drooping branchlets and others upright shoots, bearing gorgeous wands of bloom in their season. These combinations are of iron-clad hardiness, never losing even a terminal bud from zero weather, and we appear justified in expecting from them some thoroughly worthwhile early garden varieties.
Hybrids of R. Hugonis with the Rugosa roses develop into vigorous bushes with rank, green foliage and large, light yellow or white blooms, double and single, rarely followed by fruits. While fine and distinct plants, the flowers lack the texture and finish of the R. Hugonis-R. spinosissima crosses, and must take second rank. Hybrids of R. Hugonis with rose varieties of the florist's types, as far as bloomed, bear flowers more curious than beautiful and often are very poor growers. This may also be said of the blends of R. Hugonis and the Persian Yellow varieties, though much was expected from the combination of these oriental types of hardy yellow roses.
Rosa xanthina, the late Frank N. Meyer's hardy Chinese yellow rose, is even less encouraging than R. Hugonis. Seedlings and hybrids give blooms ranging from white to sulphur-yellow, with an occasional double form having flowers much like Harison's Yellow, but they show little advance in the type. The bush, however, is very sturdy, and the young shoots often have showy, wide, dark red, translucent prickles like certain forms of R. sericea. Let us hope R. xanthina will do better in the future.
Another seedling of Harison's Yellow has bloomed, the flowers taking the form of an inferior, semi-double, salmon-pink Scotch rose, thus carrying out the idea of the preponderance of R. spinosissima rather than Persian Yellow on the parentage. The seedling described in the 1919 Annual was very fine this year, exceeding Harison's Yellow in abundance of bloom and maturing several fruits, all carefully pollinated with other yellow varieties. As noted, the color is a shade lighter and the texture of petal firmer, but in other respects this promising variety greatly resembles its seed parent, though more fruitful.
This entire group of hardy Asiatic yellow roses has promise for the garden, but except by extreme dilution—as in the case of the R. Pernetiana type of bedding varieties—shows little tendency to develop the ideal buttercup-yellow continuous-blooming bush and climbing roses we all desire. When they materialize, as in all probability they will in the fullness of time, it will more likely be as mutations or developments of the Tea and Musk rose groups, though at present these are generally lacking in hardiness. Possibly the ideal yellow rose may be a final blend of nearly all the species having yellowish blooms.
|*See Plate VII, facing page 31, for "W. S. 18"|
The utility of R. Soulieana has been mentioned in previous notes. While the type of this vigorous, free-blooming member of the Musk rose group is far from hardy, hybridization with appropriate species gives progeny highly resistant to cold. One desirable variety, "W. S. 18,"* was briefly described in 1919 and more than holds our good opinion. Another very dwarf constant-blooming hybrid has appeared, rivaling the best of the white-flowered "Baby Ramblers" in continuity, profusion, and perfection of bloom. The flowers are double, white with sulphur-yellow base to the petals, and cover the plant throughout the whole growing season.
Of all species, however, R. Wichuraiana gives the most satisfactory direct results when pollinated with superior florist's and bedding roses. Several most attractive new varieties that should measure up with the best of their class await at Bell some equitable method of general introduction, and it is likely more will follow; but the work here is primarily not in competition with professional and amateur rosarians in the production of garden novelties, but in the ultilization of rare and little-known species in laying the foundation of strains of disease-resistant and hardy roses adapted for the diverse climatic and soil conditions of our vast country. Although immediate results may not be impressive, it is not without hope that development of these new types will continue, and yield rich rewards as long as civilization endures.
|PLATE VII. New Hybrid Rose, "W. S. 18" (Rosa Wichuraiana x R. Soulieana)
Originated by Dr. W. Van Fleet