Rose Annual 73: 120-126 (1988)
A THORNLESS FORM OF FORTUNIANA
Dr. Robert E. Basye
P.O. Box 494
CaIdwell, TX 77836
Having recently taken up scholarly research in rose genealogy and horticultural history, Robert Basye is a man with a clear goal in mind. He has remarked that he has ten good articles left to contribute to future rose annuals. This rendition is part two of his planned series, and the fervor with which he throws himself into these scholarly works is evident in the enthusiasm that shines through.
Robert Fortune, the English plant explorer, found this rose in China. Of it he wrote, "The white climbing rose referred to is cultivated in gardens about Ningpo and Shanghai, and is held in high esteem by the Chinese; indeed, it is one of the best white kinds which I have met with in China.'' He sent this rose to England in 1850.
Just when it came to America is not clear, but I do know that it was growing in Texas by 1890. In 1940 my rosarian friend, Albert Blumberg, drove me down to his ancestral home in the country near Hempstead. The house had burned down, and only the stone chimney remained. Close by grew a fine specimen of Fortuniana, marred only slightly by the browsing of cattle. My friend said that his mother had planted that rose the same year he was born, in 1890.
After World War II this was one of the first roses I planted in my new garden. Next to three plants of Rosa laevigata I set two plants of Fortuniana. With more foresight I would have set all five plants 20 feet apart instead of a meager ten feet!
Fortuniana is thought to have originated as the cross, R. banksiae x R. laevigata, species which are both native to southern China. To test this assumption and perhaps recreate Fortuniana in a thornless form (mainly to serve as an improved understock), I needed R. banksiae in its thornless form. I soon acquired the double white and double yellow forms, easily found since they are superbly attractive as landscape plants in the South. They are both thornless. But they are essentially sterile. I needed R. banksiae in its single, thornless form.
In the summer of 1952 1 paid a visit to the campus of the University of Santa Clara. Here Father George Schoener had moved his interesting collection of roses from Santa Barbara in the late 1930's. The gardener on the campus who assisted Father Schoener with his roses was Frank Betancourt. I asked Frank if he had the single banksia rose in the Father's collection. "No," said Frank, "but I started a bush for the Carmelite Convent a few blocks from here. It is growing there now. But the Carmelites are very reclusive and would not allow you in their garden. They allow me only because I take them flowers and plants for their garden. But I will be glad to root a cutting of it and mail it to you?"
Knowing that men can have the noblest intentions yet fail to follow through on such a promise to a stranger, I told Frank that I would at least like to give it a try. All I needed was a single bud stick to bud an understock when I returned home.
I soon came to the high, forbidding wall that surrounded the convent. I turned right to follow the wall and soon came to an open driveway leading into the grounds. I walked in, losing courage with every step, and no one in sight to restore it. Finally I came to a dead stop. I could advance no further into this den of lions, but neither could I retreat without my beloved single banksia. The next five minutes were the longest I have spent on this planet. Then suddenly the impasse was broken by the Angel of the Roses (I have never seen her, but I know she is out there.) A pair of nuns came tripping by, heading for a building nearby. I had to raise my voice to be heard. No, they knew nothing about a banksia rose or Frank Betancourt, the gardener. After an embarrasing moment one of them said, "If you will wait, we will ask the Mother Superior to come out and talk to you?' They proceeded into the building, and sure enough, presently the white-haired Mother Superior appeared and came over to where I was standing.
I had no sooner mentioned Frank Betancourt and the banksia rose than the Mother's face lit up, and she replied warmly, "Of course we have his banksia rose; come with me and I will show it to you," and she led the way into the inner garden of the convent. Alas, her rose turned out to he a double banksia, and I had to explain why I needed the single form. She was convinced that she did not have the single, wild form but seemed much interested in it. "Would you please tell Frank that I do not have it, and that I hope he can bring me a plant?"
I promised that I would and thanked her for her courtesy. As I left the convent I felt as much a sense of success as of failure, and I was reminded once again how the universal love of the rose can be a password to almost any place on earth.
I returned to the campus to convey to Frank the Mother Superior's wish. His reply: "She has it there now because I planted it.'' And he renewed his promise to send me a rooted cutting. The rooted cutting never came, but to this day I suspect that Father Schoener's single banksia rose may still be living in the convent garden.
Knowing of no other likely source of R. banksiae in America, my thoughts turned to the Italian and French Rivieras. I knew that banksias flourished there and that Fortuniana was a favorite understock. I wrote a letter to Domenico Aicardi, the Italian rose breeder who produced Rome Glory. Signora and Eternal Youth. This kindly old gentleman, then in his upper seventies, responded by sending me a generous handful of banksiae seeds, which must have taken him several hours to extract from the very small hips of banksiae. I have never forgotten his generosity.
I was soon to learn that the seeds of banksiae, like those of laevigata, will rarely germinate the first winter after harvest and must he held over til the following winter. Among the Aicardi seedlings some were single white, some double white, some single yellow and some double yellow. About half were thornless. And some were both single and thornless.
In general, both banksiae and laevigata are quite reluctant to cross with other species. But they cross very easily with each other. Through the years I have grown several hundred seedlings of R. banksiae x R. laevigata, always using a single, thornless banksiae. All bore a close resemblance to Fortuniana except that the flowers were single. The double flowers of Fortuniana may have come from a banksian parent which was double. All the seedlings were thorny, as might be expected. Rarely would a cross bear a hip or two, but even the few F2 seedlings had thorns.
Then in 1969 I obtained a seedling (69-348) of R. banksiae x R. laevigata which was not so stingy in producing hips. But the seeds rarely sprouted, the reason being, as I soon learned, that most of them contained no embryo. Nevertheless, in 1984. two F2 seedlings were produced, one of which had a few thorns and the other of which was completely thornless, with perfectly smooth midribs of the leaves. The latter rose bears the number 85-04 and is the subject of this article. I shall call it simply 'Thornless Fortuniana.'
The 21 somatic chromosomes of "Thornless Fortuniana;" photo by Kenneth Highright, using leaf tips
I thought surely 'Thornless Fortuniana would prove to be a diploid, with 14 chromosomes, as is 69-348 and Fortuniana. I was quite surprised when the somatic count showed that it was a triploid, with 21 chromosomes! One explanation might be that it arose as an outcross, 69-348 x (some tetraploid). This is highly unlikely for three reasons. First, 69-348, like its parents, blooms very early and is through blooming before most roses begin. Second, 69-348, like its parents, is reluctant to accept foreign pollen. And third, the influence of an outside pollen parent should be readily apparent, even to an amateur. On the contrary, 'Thornless Fortuniana' appears to be an exact replica of Fortuniana except 1) the thorns are missing, 2) the flowers are single, in contrast to the double flowers of Fortuniana, 3) the leaves are slightly darker green and glossier, and 4) the chromosome count is 21 instead of 14.
I believe that the triploidy of our rose must be explained by the rare occurence of an unreduced gamete, either male or female. I am inclined to believe also that the presence of 21 chromosomes in the zygote may have been the very secret which led to a viable embryo and seed. This belief is reinforced by the fact that the only companion seedling of 69-348, mentioned above, also turned out to be a triploid!
Fortuniana has been used as an understock in Western Australia since 1903. Its excellence for that region has been so well established through the years that today all the nurserymen there use it, despite its handicap of being a bit difficult to strike root from hardwood cuttings. For an excellent account of the story of Fortuniana in Western Australia, see "Roses and Fortuniana Root Stock," by Charles A. Newman, The Australian Rose Annual, 1984, pp. 53-55. Charles A. Newman is the son of Charles Lewis William Newman, who pioneered the use of Fortuniana around 1903. See also the article by F.M. Daw in the same Annual, 1979, pp. 91-92. For a detailed account of the history of Fortuniana, see the article by Daniel Morrell in the American Rose Annual, 1983, pp. 55-72.
Fortuniana has also been used as an understock in the Italian Riviera and in Florida where it has the reputation of being resistant to nematodes. Mostly, however, nurserymen are reluctant to use it, not only because of the rooting problem. but also because the budded plants cannot be shipped very far north. But amateurs who live in the South should by all means explore the virtues of this rose. I have used it for 40 years and rank it as superior to any other understock I have ever tried. For many years I have used nothing else.
The nurserymen of Western Australia prefer hardwood cuttings for labor-saving reasons. Callousing them first for a month or so in a special kind of sawdust was found to increase the strike rate. They are then set in the field before the roots appear. The success rate will depend on selection of the wood, weather and cultivation, See the article by F.M. Daw mentioned above.
The amateur, requiring fewer understocks, can use either hardwood or softwood cuttings. Softwood cuttings 6 to 8 inches long should be taken before the first freeze. Leave the upper two leaves and slice out the lower buds. These two leaves and the wood should he both prime and mature. The basal cut is best made just below a bud. Since the cuttings are rather susceptible to infection at the basal cut before they callous, I would urge consulting with professionals in floriculture as to the best rooting medium and also the best techniques of handling. After many years of variable luck at rooting Fortuniana, I am convinced that I have still not found the best way short of a misting system.
Fortuniana endows its scions not only with uncommon vigor and longevity, but also with another virtue I have not seen in any other understock. Under favorable conditions most of the scions will push out and start growing within a week or two. By autumn it is not at all uncommon for one year plants to have the size and growth of two-year plants.
"Thornless Fortuniana," photo by Robert Basye, Caldwell, TX
Fortuniana does have one unpleasant feature, a strange phenomenon pertaining to its thorns, which I do not understand. Like most understocks it will occasionally sucker from below the union. Sometimes this sucker has the normal growth of Fortuniana and is, I believe, usually the result of not having properly sliced out a normal leaf bud when preparing the cutting for rooting. This kind of sucker often appears during the first year. But occasionally a sucker and all future side-growth from it will be hideously thorny! This never happens during the first year, only in later years. I suspect that such a sucker does not originate from a normal leaf bud, but rather from some inconspicuous adventitious bud which is forced into growth by an emergency, such as a weak or aging scion. Can some geneticist or morphologist throw any light on this Dr. Jekyll and Mr. Hyde phenomenon? I carefully avoid taking propagating wood from these occasional renegade suckers, and they have never contaminated my normal understocks.
One saving grace here is that no sucker, either normal or renegade, ever issues from the root itself. When a budded plant is removed by cutting the roots, no new growth will ever appear.
Returning to 'Thornless Fortuniana', it is much too new to judge its value as an understock. I cannot promise that it will even approximate the excellence of Fortuniana or that no future thorn will ever show or that its seven extra chromosomes will make it slightly hardier than Fortuniana. The testing should be done over a number of years, in different parts of the country. Rosarians who live in the South and have understocks may request bud sticks whenever their bark is slipping. Do not reimburse me for the postage. Instead, pass the rose on to a friend.