THE HYBRID LARKSPUR
AND OTHER TRANSFORMATIONS INTRODUCING A MISCELLANEOUS COMPANY
The members of my larkspur colony are all descended from a single individual. That individual, in turn, was the select and peerless member of a company of five thousand, all of them of equally aristocratic lineage, and each one of them worthy to show itself in any larkspur company. But the usual rigorous method of selection was applied to them. The one individual that came nearest meeting all expectations was preserved. The rest were sent, with sundry thousands other plants of divers species, to the bonfire. The selected individual, of course, became the progenitor of a new colony of larkspurs. Some of these improved upon their ancestor, and among them several interesting varieties were isolated through selection. The original parent form from which the one best larkspur was selected as the progenitor of new races was of the species known as Delphinium hybridum, or hybrid larkspur. As the name implies, this plant is itself of hybrid origin, but it has been cultivated a long time in Europe, being unusually popular in England, and ranks as a true species, or at least as a good horticultural variety. There are numerous other species of larkspur, sixty or more altogether. Some are annuals and some perennials. Our native California species are among the most beautiful. One of these, named nudicaule, is a perennial growing along the sides of streams and in shady canons, although on occasion even mounting to the tops of high rocks. It bears flowers of a bright orange red, sometimes varying to yellowish, that are very showy. The plant is easily cultivated either from seed or by division, as indeed are all perennial larkspurs. Another species is D. cardinale, a large, strong plant, growing in the southern part of California, the flowers of which are also bright red and yellow though quite different in general appearance from those of the one just named. Yet another larkspur that is of interest is the D. decorum, an extremely variable form growing usually on overflowed land. The flowers of this wild species vary almost as much as do our hybridized and cultivated ones. Growing side by side in a bed of wild larkspurs of this species may be found plants bearing flowers varying from deep blue, pale blue, dark rosy pink, pale pink, and yellow, to almost pure white. The flowers of these are quite large and showy, but the colors, although so variant, are seldom brilliant. The larkspur known as D. Californica is a giant species, often found in canons toward the coast. For a larkspur it towers to a great height, sometimes reaching seven or eight feet, but the flower is insignificant when compared with most other varieties both in size and color. They are purplish blue or dingy white in color. My attempts to cross this species with some of our cultivated ones have not resulted in producing anything of value. Still another species is known as D. hespirium. It grows in sandy or heavy black soil as the case may be; is about two feet in height, and bears flowers that are almost invariably of deepest blue, although sometimes pink, pale blue, and white ones are found. These wild species are mentioned somewhat in detail, chiefly to show the variation among them, suggesting the possibility of interesting developments when the various forms are combined. I have utilized them all more or less in experiments, and in addition have grown nearly all the larkspurs that are ever offered by seedsmen or florists. As already stated, my chief experiments began with the use of the hybrid larkspur as a seed parent, but of course the hybridizing experiments soon blended the strains of many of the other species, until the larkspur colony, like so many others of flower groups, is of such conglomerate ancestry that the precise proportions of the different strains in any given race are not traceable. Needless to say, selection has been carried forward along with the hybridizing experiments, these two methods always being complementary. Particular attention has been given to size of flower, vigor of plants, and resistance to insects and disease, as well as that of multiplication by division, at the same time that compactness of growth and brilliancy of color of flower have been carefully regarded. One of the worst faults of the larkspur is that it tends to grow too tall, with a stalk-that does not support it, so that it requires to be staked. But my hybrid larkspurs have been so selected that they are compact in growth, and able to support themselves even in a moderate gale. All the characteristic larkspur colors are represented among the new varieties, and in addition there are combinations of color that have never before been seen, I think, in the larkspur. Some of the individual flowers are considerably over two inches in diameter, and some of the largest are very double. The color yellow is not usual with the larkspur, its characteristic colors being red, blue, and white. There is one yellow species, a native of southern Asia. I have, however, developed varieties with pale yellow flowers. The best of the selected varieties, as descended from the original one chosen among the first five thousand, is known as Burbank's hybrid, and has been given full recognition by seedsmen, florists, and gardeners. There is still opportunity for further development among the larkspurs, however, and improvements may be expected which, if not spectacular, have at least a fair measure of interest. No plant is ever so fully developed that it does not hold possibilities of improvement.
AN ALMOST ENDLESS VARIETY
The great family of composites presents an almost endless variety of flowers, of which we have seen some striking examples, most notable among these being perhaps the daisies and the dahlias. But now and again a new form makes bid for popularity, and there is still an indefinite amount of material among our wild plants from which garden plants might be developed. Yet the old favorites are not necessarily supplanted. Indeed there are some of them that have perennial interest, holding their charm despite all competition. One of these is the marigold, of which there are various species that find favor not only because of the ease with which they may be cultivated, but also because of the length of time during which they bloom, the abundance of blossoms, and their good keeping qualities after being picked. The marigolds most commonly cultivated fall into two distinct groups, one spoken of as the African marigold and the other as the French marigold. In addition to these there are native species, among others a very interesting one that I have received from Arizona, sent me by Professor Lemon, whose name it bears. This native form is a shrub about four feet in height, and in the fall it bears a mass of beautiful single golden flowers about the size of the French marigold. This is one of the handsomest shrubs of this sort, and although I think it has not yet been introduced, it deserves a place in every garden, if-as has not yet been proved-it will stand the colder climate. My experiments with the marigold were conducted a good many years ago, chiefly along the line of crossing the French and African races and this new Arizona perennial species. In addition to their practical horticultural results, the experiments gave some interesting illustrations of hereditary influence, In particular I observed that when the double marigolds were crossed with the perennial single species above mentioned all the hybrids were single. Moreover, if I am not mistaken, they were all annuals, though the perennial marigold was the mother plant in every case. It is interesting to recall that precisely the opposite result was produced in hybridizing the poppies. In that case the union of an annual and a perennial poppy produced hybrids all of which were perennials. One of the best marigolds with which I have worked is called the lemonball. It is of the African type, and it produces great lemon-yellow blossoms in abundance, blooming throughout the entire season. The best specimens are thoroughly double, but if the seed is saved from the most double blossoms, almost half of the seedling will bear single flowers or those not perfectly double. It is obvious that the factors for singleness and doubleness tend to be segregated, and that the strains of the double marigold have not all been isolated in such a way as to produce germ plasm that is unmixed as regards the factors for number of petals. Presumably this could be done by careful selection. My more recent experiments have to do with the general improvement of the marigolds, and I am also experimenting with a new species from Chile with reference to its possible value as a pot-herb for its fragrance and flavor. It is a tall, sleiider shrub with innumerable pale, straw-yellow flowers-almost white. Like one or two other species of the genus it has a most delightful fragrance and flavor. As regards quality and intensity of flavor, it surpasses all others, but it apparently has no other merit. Whether it will prove of sufficient value for introduction in the vegetable garden is still problematical. A much less familiar member of the composite family which, however, has gained rapidly in popularity in recent years is the plant known as cosmos. This is a Mexican species that is now making its way into the flower gardens everywhere. It is related to the plant known as the black dahlia (Bidens astrosanguinea) botanically, yet the relationship is not so close that the two can be combined, at least I have not been able to effect crossing between them. A peculiarity of the cosmos, due doubtless to its recent importation from a sub-tropical region, is its habit of blooming very late in the autumn. This is sometimes regarded as a merit, but as the plant is very tender, there is danger that its blossoms will be blighted by the early frosts. So the most important work that has been done with the plant in recent years is the production of early blooming varieties. The effort has been so far successful that there are now varieties that bloom in midsummer. The fact that this modification has been brought about within a comparatively few plant generations illustrates the pliability of the cosmos. It is, in point of fact, one of the most variable and pliable of plants-comparable in this regard to the dahlia. Such being the case, it is not surprising that it has been found possible to develop new shades of color, as well as much larger and finer flowers than those of the original species. Forms with wider petals, and others with twisted petals and other variations of the corolla, have also been developed. Even a double cosmos has been mentioned as forthcoming. But the plant is comparatively new in the flower garden, and it offers therefore rather exceptional opportunities for the experimenter. The amateur who is looking for a plant that has not been carried to anything like its limits of variation may advantageously pay attention to this graceful, attractive, and rapid-growing composite. The extreme heat and long days of the summer even in high altitudes in the United States makes possible the cultivation of a large number of flowers that were originally of tropical habitat. Among these no others are more familiar or have retained their popularity more steadily than the tribe of plants of the genus Iponoea, which numbers among its representatives plants of such diversity as the morning-glory, the moon-flower, the cypress vine, the yam, and the sweet potato.
THE BRILLIANT MORNING GLORY
It is not difficult to account for the popularity of the morning-glory. A vine that grows with the greatest rapidity and that bears flowers of striking and brilliant color in the greatest profusion, day after day, for weeks together, covering our arbors or pergolas in a few weeks' time, has merits that are not duplicated exactly by those of any other flower under cultivation. The morning-glory has not been very extensively worked with, but it has shown a marked tendency to variation, and, as usual with plants under cultivation, has broken up into numerous varieties, showing in particular a wide range of color variation. One of the most remarkable of the varieties is the Japanese morning-glory, some forms of which have double flowers of very curious structure. The single varieties of the Japanese type are of relatively immense size and of the most wonderful color. But they do not produce so abundantly as the common morning-glory, they do not climb as well, and they seem to lack the vigor of the ordinary form. My experiments with the tribe have had to do with the crossing of several related forms. The plants can generally quite readily be crossed, and the seed germinates readily. These experiments have not been carried far enough to produce any very striking results. It is obvious, however, that the morning-glory offers good opportunities for improvement, and the ease with which it can be cultivated makes it a plant that should appeal particularly to the amateur. The wide range of color variation, together with the fact that the colors are fairly fixed in certain varieties, make possible crossbreeding experiments that can readily be checked. Possibly also it may be feasible to cross the morning-glory with the moon-flower or with various other members of the genus. The moon-flower itself, which produces large white flowers in great abundance, has been greatly improved by selection. There is also an interesting Brazilian morning-glory (Ipnoea setosa) with a vine that grows with great rapidity and bears a rosy purplish flower, and a perennial tree morning-glory, a native of Texas, which bears very large light pink flowers in abundance. Indeed the number of species from which selection can be made is rather large, and variation among them sufficient to give the experiment in hybridizing exceptional interest. Another vine-like plant from South America that has made its way into every garden is the Tropaeolum, commonly known as the nasturtium. There are at least forty species of this tribe, mostly climbing natives of Peru and Chile. One of these, T. puberosum, produces spicy roots that are highly prized as foods, and its seeds are sometimes used in salads under the name of Indian cress. The seeds of the form familiar in our gardens are sometimes pickled, and it is probable that table products of greater value could be developed from these plants if attention were paid to breeding them with that idea in mind. Some of the nasturtiums are exceedingly tender to the slightest chill, but they may grow in the hottest and driest soil. My work with the nasturtiums has been done with specimens sent from South America by my collectors, representing eight or nine species. Some of these have bulbs that remain dormant in the ground for two or three years, and then sprout and grow very fine vines that climb over the bushes. The common nasturtium of our gardens, T. majus, is one of the most readily grown of our annuals and has been so long cultivated and so thoroughly crossed that the colors of the flowers are exceedingly variable. In recent years very good work has been done, particularly by California cultivators, in the improvement of the climbing nasturtiums, and in particular by crossing the ordinary form with the one known as T. millus. Both the parent forms and the hybrids have run into numberless colors, clear lemon yellow, flesh color, deep crimson, purple, scarlet, deep yellow and white, the colors being variously blended, and the foliage of the plant being sometimes most beautifully variegated. Even the form of the leaf has been changed, so that there now are ivy-leaved strains of nasturtiums. The nasturtiums offer great interest for the amateur experimenter, as they are very readily hybridized, and as their range of variation, even without crossing, is so great as to afford the widest opportunity for selection. Indeed, crossing has been so fully carried out that for ordinary purposes selection will answer far better than further crossing. Indeed it is exceedingly difficult to keep the colors of the various nasturtiums separate. The seed of a pure white variety quite commonly may produce various colors. And it is more difficult to fix these colors than is the case with most other flowers. But of course such difficulties only enhance the interest of a really earnest experimenter, and develop his enthusiasm.
STAMPING PERSONALITY ON A FLOWER
An illustration of the way in which the personality of the experimenter finds expression in the plants that he cultivates was furnished me a number of years ago by Mr. Peter Barr, a well-known horticulturist who specialized with the narcissus and daffodils. On visiting my place a number of years ago, he related an experience that may be taken as typical, yet which the amateur who has not experimented extensively might regard as rather extraordinary. The story has been told in an earlier volume, but it may be briefly repeated here. Mr. Barr stated that among the thousands of seedlings the whole stock of which he purchased of two specialists in England, he could always tell at once, on seeing the blooms, which of the two specialists had developed any individual plant, even though the varieties had been mixed. One of the breeders produced very large, coarse flowers, gigantic and broad, and lacking in delicacy of contour. The other produced seedlings of graceful and exquisite form. And these contrasting characteristics of the different daffodils, Mr. Barr assured me, typified the personalities of the two breeders by whom they were developed. One of these was a person of little refinement, notwithstanding his love of flowers; the other was a cultivated banker of artistic temperament. The tastes and propensities of the two men made themselves felt in all the flowers they produced; which of course was inevitable, when we reflect that the plants were produced by selection, and that each man naturally selected the type that appealed to him. I cite the incident not as something exceptional, but as typical. Almost as a matter of course, one could draw correct inferences as to the personality of a plant developer from observation of the varieties that he has developed-provided always, of course, that his selections have been made along the line of his own tastes, and not to meet some specific commercial demand. There should be for the amateur an added stimulus in the reflection that he is thus putting the stamp of his own personality upon the plants with which he experiments. The flowers of your own garden may thus come to have an individuality that represents you as fully as you are represented by your costume or by the books you gather on your shelves. And surely the possibility of developing a flower garden that has such individuality, differing from any and every other flower garden in the world, should give the pursuit of the amateur florist unique interest.
SOME INTERESTING NATIVES
I have more than once suggested the possibility of introducing to the garden species of plants that grow in the wilds and that offer interesting possibilities of development. Two or three other tribes of these interesting wildlings may be here referred to. To name all that are worthy of consideration would take many volumes for there are more than ten thousand species of flowers indigenous to the United States, and of these only something like fifteen hundred have at one time or another been placed under cultivation. I may name two or three familiar ones, in addition to those that have already been referred to, as offering exceptional attractions. There are, for example, the Gilias, represented by many species. I have cultivated twenty or more wild ones at one time, selecting for brilliancy of color, for size of flower, for compactness of growth, or for some other desired quality. On occasion I have carefully scrutinized at least ten thousand different plants in order to select the individual with which to begin improvements. The gilias vary greatly in color, so that they are very interesting flowers with which to work, and the colors may very readily be fixed in the course of four or five generations. So also may the qualities of compact growing, size of flower, and the like. The plants, therefore, are encouraging ones for the amateur who is anxious to get results. The familiar milkweeds have been referred to in another connection with reference to the peculiar arrangement of their pollen masses, which are so adjusted as to entangle the feet of bees. The amateur will find it peculiarly interesting to cross-pollenize these flowers. It will be advantageous to work with a magnifying lens of considerable power. The curious form of the flower and the unique arrangement of the pollen masses give the work of cross-fertilizing these plants a unique character, and these flowers are in general among the most puzzling of all flowers for the amateur. There is possibility of developing, among the milkweeds, plants of commercial value. I have worked somewhat extensively with a number of unclassified South American species. For two or three years I carried on the work of selecting the best seedlings among a large number, until several races were pretty sharply defined. Now I am crossing the best of these, the object being to get varieties of more beautiful blossoms for garden culture, and also to secure varieties that will be of value in producing a fiber that has something of the quality of silk. Even now tons of milkweed seed pods just before they are ready to open are dried in the Mississippi Valley and shipped to Japan, where they are used to make a kind of felt. In the Philippines there is an allied plant, the Kapok, which supplies a fiber much used for filling pillows and the like. It is considered within the possibilities that a variety may be produced that will be of value for the production of rubber, as the juice of some species has excellent rubber qualities. The native varieties of milkweed are exceedingly hardy and as they are perennials they may be worked on season after season. There is great variation as to vigor of growth, size of leaves, compactness of plants, and color and form of leaves, as well as regarding the size, color, and abundance of blossoms. The seed pods, with their white, silk-like fiber also vary greatly. And there is corresponding variation as to the amount of latex or milk produced by the stalks. All in all, then, there is scarcely another tribe of plants that shows a wider range of interesting qualities for observation of the experimenter. Another wildling offering attractions of a different character is the so-called painted cup, or Indian's paint-brush, classified by the botanist as Castilleia. The most familiar form of this plant is the one known for its brilliant scarlet color. But the tribe is exceedingly variable, and the different members present flowers that range from scarlet, crimson, orange, yellow, and purple to pure white. Some are variegated. Individual plants of the first named species growing on the same cliff along the shore may show the widest range of variation in the color of their blossoms. Indeed, all colors are sometimes combined in the flowers of a single plant. In other cases one will find a small patch of yellow flowers in one place, and in the neighborhood another patch of orange colored or of white ones. The only color that is missing is blue. It would thus be an interesting quest for some plant developer to see whether he could develop a blue painted cup, somewhat as I was able to develop a blue poppy. Even failing in this, the opportunity to study heredity of color, and to isolate races of painted cup of one color or another, attempting to fix them so that they would come true from seed, would give recreation for a number of seasons. The fact that the painted cup does not always prove easy of cultivation suggests that it is a plant worthy the attention not merely of the beginner but also of the amateur who has gained a measure of experience, and who is willing to try his hand at problems of plant development that are not free from difficulties. As I said before, it would be possible to extend almost indefinitely this list of interesting flowers that invite development. But the ones named may serve by way of introduction, and the amateur may readily extend the list by looking about in almost any garden or by rambling almost anywhere along country roads or in neighboring fields.
-The material lies everywhere about us, and despite the activities of large numbers of flower lovers, there are hundreds of species readily accessible that have never come under the hand of the cultivator, and which therefore have the attraction of entire novelty.
This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 10 Chapter 6