THE CANNA AND THE CALLA
AND SOME INTERESTING WORK WITH LILIES
My most celebrated canna is the one named the Tarrytown. This canna took the grand gold medal at the Pan-American Exposition at Buffalo, as the best canna exhibited at that time. There were large numbers in competition. In addition to receiving the gold medal, the Tarrytown was given special mention as being the most profusely blooming canna ever seen. The new canna is a rich brilliant crimson in color, and is rather dwarfed in size, standing not higher than three feet. Instead of producing a single stalk or at most three or four stalks, as a good many even of the better varieties of canna did at the time when this was produced, the Tarrytown grows from six to nine off-shoots of the main stalk. Thus it makes a splendid and highly effective display. The individual flowers are of good substance, enduring the sun well. After the blossoms fade, the petals drop to the ground. This is a special feature for which careful selection had been made, as many cannas tend to hold shrivelled blossoms, thus having an untidy appearance.
ORIGIN OF THE NEW CANNA
The Tarrytown canna was developed from the type known as the Crozy canna, hybridized with a native species of the Florida swamps known as Canna flaccida, a plant with extremely large flowers of pure lemon yellow. The Crozy canna is a well-known horticultural variety, developed in somewhat recent years, which differs from the varieties that were previously in vogue in that its flowers are notable attractive and of varying colors. Until the cannas of the Crozy type were developed, this plant was prized chiefly for its foliage, the flowers being rather insignificant. But the Crozy canna has large flowers, to casual inspection similar to those of the gladiolus. The Florida species (C. flaccida) that was used to hybridize with the Crozy, has very fine large petals, but the flowers are not lasting. But it blended well with the other type, and introduced an element of variability that facilitated selection and development along the lines similar to those characterizing the perfected Tarrytown; also the Burbank, Austria, and Italia, since introduced. The Crozy canna is itself a hybrid, one of the parents, I believe, being a form known as Canna iridiflora, a tall plant with long, dark green leaves, and with a long drooping panicle of rich crimson flowers. I have experimented with this form, but have never known it to produce seed. The developer of the Crozy was apparently more successful in this regard, and in going forward with the experiments I was enabled to profit by the earlier hybridization. The new hybridization that I effected between the Crozy hybrid and the native Florida species, brought together strains widely diversified; for most of the cannas are of tropical origin. The tendency to variation was very obvious even in the first generation, as might have been expected considering that one of the parents was itself a hybrid. From the same hybrid strain it was possible to select a number of plants showing individual peculiarities that seemed worthy of perpetuation. The qualities developed in the Tarrytown have already been outlined. Another race developed simultaneously, through a different series of selections, differed very markedly, in particular as regards the character of the flower, which took on so characteristic a form, and colors of such elusive quality, as to merit the name of Orchid-flowered Canna. It chanced that experimenters in Italy produced simultaneously and quite independently a race of canna having closely similar qualities. The best of my cannas of this type was introduced under the name of The Burbank. This plant rather closely resembles a variety known as the "Austria" which was introduced about the same time from Europe. The Burbank, however, is somewhat larger, and has thicker and more rubber-like foliage; and its flower its slightly less crimson in the throat.
WORKING WITH THE CANNA
The cross-fertilization of the canna should seemingly present no particular difficulties to anyone who studies the mechanism of the flower. The stamens have a petal-like appearance, and the pollen-mass could not be transported by the bee or any other small insect. Large moths may carry it from one flower to another, but the usual pollenizer of the canna, in this country, is the humming-bird. The hand-pollenizer may readily enough detach the pollen-mass, and transfer it to the stigma of another flower. But it does not follow that hybridizing is easy. In point of fact I found it exceedingly difficult, especially when attempting to cross the ordinary canna with the Florida species already mentioned. I worked for eight years with that purpose in view before succeeding. And even then the seedlings were greatly lacking in fecundity, producing very little seed, notwithstanding the fact that cannas in general usually produce abundantly in California. The infecundity of the canna hybrids suggests that the species in question are almost at the limits of affinity. But the seeds produced, although few in number, were some of them fertile, and the hybrid progeny showed possibilities of development, as already suggested. The later generations, however, are almost or quite sterile, refusing to seed. The chief difficulty in growing seedlings of the canna is to insure the germination of the seed. The familiar name "Indian-shot plant" by which the canna was first known suggests the character of its seeds, which in point of fact are not unlike small bullets in appearance and in hardness of texture. The old plan of germinating the seeds used to be to file off part of the thick shell, in order that the seed might absorb moisture. This works very well, but can hardly be applied on a large scale. My own method has been to disinfect the canna seed with a solution of blue stone (sulphate of copper), and place them in coarse gravel, taking pains to pour water through the gravel at frequent intervals. Under these circumstances, the seed is less likely to decay through attacks of fungous pests than if planted in the soil. In the coarse, clean, sterilized gravel, a high percentage of the seed will come up in a few months. The porosity of the gravel, giving free access to air, is also an element that is advantageous to the seed of the canna. Seed treated in this way will germinate at a relatively low temperature; but germination is facilitated if the heat is kept between sixty and seventy degrees. As soon as the seedlings appear, they are transplanted thinly into boxes where they are allowed to stand until May, when they are planted in the field, and cultivated like other crops. A large proportion of the seedlings will prove worthless. The weeding out of the first year is done readily, but selection in the second year requires skill, to judge as to which plants are worthy of preservation. Beyond that, of course the usual process of selection through several generations will be carried out along the lines of the desired modification at which the experimenter is aiming. The objects that the experimenter may advantageously bear in mind in developing new cannas, include hardiness, the production of a double flower, and the production of a white flower, among others. In California the canna may be left out of doors over winter; indeed it does much better when so treated than when the bulbs are lifted and stored. In the northeastern States, it is necessary to dig the roots and store them where they will not be subject to too low a temperature. It will be of advantage to develop the canna to a stage of hardiness that would enable it to be treated as an ordinary perennial, leaving the roots in the ground and only dividing them now and again for purposes of propagation. Still this might require more work than is worth giving to the task, inasmuch as the canna is already grown far to the north, and the work of digging and storing the bulbs is not excessive. A double canna would certainly be a novelty and one that is probably worth working for. The same is true of a pure white canna. By hybridizing and careful selection, it should be possible to develop this novelty, judging from analogy with other flowers. Of course it is possible to increase the size of the flower, and to produce other color variations along the line of recent developments. Most important of all, the flower should be made more lasting. The manner of production of my fragrant calla was described in an earlier chapter. It will be recalled that this anomaly was produced through selection from an individual found among a large company. The question of odor and its variation in flowers was further discussed in a recent chapter. There appears to be, in point of fact, as wide a range of variation among flowers in the matter of odor as in regard to color. But inasmuch as most selective experiments have been made with reference to color and quite without regard to the matter of odor, the cultivated plants have naturally developed along the lines of color variation, and even those that were originally fragrant have in many cases lost their perfume.
IMPROVING ESSENTIAL OILS
In recent years, however, much more attention has been paid to this matter. In particular, the studies of the chemistry of essential oils, with reference to the production of artificial substitutes for the natural ones, has given clues that the plant developer is beginning to take up. I have been invited, for example, to improve the clove and the cinnamon, as well as the coffee plant, in the production of races having a higher percentage of the various essential oils for which they are prized. Coffee, as everyone knows, depends very largely on its aroma and fragrance, and it has been found that these may be greatly modified according to the soil in which the plant is grown. The fragrant qualities are often greatly intensified when the plant is grown on volcanic soil and at a high altitude. It is known that various spices differ markedly. In the same way the quantity of alkaloids, such as caffeine and quinine, may vary in the same species under different conditions of soil and climate. There is a species of coffee that is practically without caffeine; but this has little aroma. It has been proposed to combine it with the Arabian coffee and it may be possible to produce a coffee without caffeine-which may or may not be popular. Among garden plants that are prized for their aromatic quality, the thymes vary widely in the amount and quality of their essential oils. The notable variation in the odor of the calla, which gave me my scented variety, is duplicated in a good many species of lily. The individuals even of the wild species vary, some of them having a really delightful fragrance, and some none at all. In crossing the different individuals, you may accentuate the perfume, add one element of fragrance to another; or, on the other hand, you may make such a combination that the two aromas seem to neutralize each other, producing an odorless hybrid. The plant developer who works with these anomalies in mind, paying heed to the fragrance of his flowers as well as to their other qualities, is almost certain to produce varieties that will be appreciated, for, as already suggested, the perfume of the flower and the flavors of foods are nowadays receiving more attention than formerly.
NEW GIANT CALLAS
I have introduced four main varieties of calla in addition to the calla Fragrance. My work began largely with raising seedlings for the trade, from the form of calla known as Richardia albo-maculata, a dwarf variety with spotted leaves that was at that time very popular. The leaves of this plant bore attractive white or transparent markings on the bright green surface. The flower was white, with a brown tinge at the base, and in the original form was insignificant. I raised this calla in great quantities a good many years ago, sometimes producing from the seed a quarter of a million bulbs in a season. Among these almost numberless seedlings appeared, now and then, a golden variety, but this proved difficult to fix, although very handsome and attractive. Presently I secured another variety of calla known as the Pride of the Congo, Richardia hastata. This is a much stronger grower than the other variety and has pale yellowish flowers larger than those of the albo-macuilata. I raised many seedlings from this variety on my Sebastopol place, and developed it by selection until it produced very large bulbs. Then I hybridized the two species, using our hybridized golden variety of the R. albo-mnaculata and the developed varieties of R. hastata. The cross was made reciprocally as usual, and here as elsewhere it appeared to make no difference which was the pollenate and which the pistillate parent. The hybrids vary considerably as to bulb, plant, and flower-much more so than either parent species when raised from uncrossed seed. And among the hybrids there were some plants that produced enormous bulbs, sometimes eight or ten inches in diameter and weighing from two to six pounds each. The plants that grew from these bulbs were of large size and bore blossoms that were of much brighter yellow than those of either parent. This plant was introduced under the name of the Giant Calla, a name subsequently changed to Lemon Giant. Subsequently I obtained a number of other species of calla, including those known as R. Elliottiana, R. Pentlandi, R. melanoleuca, R. Nelsonii, and R. Rehmanni. These were all hybridized with one another, and with the species that previously was in hand. Among these complex hybrids were plants that were unique in form and foliage and flower. The blossoms varied in color not only in the different hybrid plants, but sometimes an individual blossom would be partly deep purple, partly deep yellow, and in part almost white. Sometimes the colors were mottled or orange in stripes, but usually the purple color appeared in the throat of the flower. The purple is apparently a combined inheritance from the Elliottiana, Rehmanni and melanoleuca; and the hastata also has a faint touch of it. The yellow is heritage from hastata and Elliotiani. These plants varied as much in size as in quality of flower. Some of them grew three and a half feet in height, others only eight or ten inches. In some cases the foliage and stalks were smooth and in others actually hairy, covered with soft excrescences of thorn-like appearance. Some of the hybrids were very easy to raise, but most of them very difficult. Among the freak forms that appeared in this hybrid colony were plants bearing double and even triple flowers, and others in which the flowers and leaves were combined in the most curious manner. Of course the so-called flower of the calla is a modified leaf that has not altogether lost the leaf-like form and manner of growth. So the reversion through which the flowers become still more leaf-like in these mixed hybrids was perhaps not altogether surprising. But the particular manfestations of the tendency to reversion were most astonishing.
OTHER NEW VARIETIES
Among the hybrids that departed less markedly from the calla traditions, were some that bore flowers of a splendid deep yellow, and that had all desirable qualities of easy multiplication and abundant blooming. Some of these have a purple spot low down in the throat, others are a pure yellow, not dissimilar in appearance to my early varieties. But while the new hybrids outwardly resemble some of the early varieties developed by selection, they showed their inherent difference in that they are exceedingly easy to cultivate, whereas the earlier ones were subject to decay without apparent cause at any season of the year. The new hybrids are hardier, and can be raised much more readily. They will grow out of doors in any mild climate, and require scarcely more attention than so many potato plants. They are reasonably indifferent to the conditions of moisture and a moderate degree of cold does not in the least discourage them. The contrast in this regard between the newer hybrids and the earlier yellow varieties is very striking. They furnish an illustration of the added vitality that may come through hybridization. The original yellow calla is confined to a limited area in, the sub-tropical regions of South Africa. Its pure-bred descendants, as we have seen, retain the sensitiveness of the parent. But the selected hybrids, while retaining the yellow color of the African plant, have acquired from their other parental strains a degree of hardiness that adapts them to our climate, and at the same time have received increments of vigor that nothing but hybridization appears to give. As to the later point, I may mention a sport that appeared among my white callas, in the form of a plant that grew to gigantic size. The sport appeared among the seedlings of the common calla but doubtless represents a natural cross between different strains of this species. The plant bore its flowers on stems sometimes six feet or even more in height. The foliage was of corresponding size, and the flowers almost proportionately immense. The new sport was named the Giant Calla. In contrast with this giant is a dwarf of the same species, retaining the characteristics of the calla, and having the peculiar interest that attaches to a miniature flower reproducing the qualities of a familiar flower which we ordinarily think of as being of large size. Some of my dwarf varieties, produced by selection, have flowers only two inches in diameter. Among the offspring of the Giant Calla, one has appeared that has a shade of purplish crimson on the stalk and blossom. This color I have never known to appear in the common calla before, and its appearance suggests reversion to a very remote ancestor. It is possible that the giant bears blood of one of the other species, two or three of which, as before mentioned, have strains of purple in their heredity but this is unlikely, as I have never been able to get these species to cross. It will appear that there is abundant opportunity for the making of interesting experiments with the different races of callas. As to the practicalities of cross-pollenizing, there are no difficulties, notwithstanding the very curious character of the floral envelope. The calla flowers, as is well-known, are very tiny, and borne on the central spadix that stands like a little post in the center of the leaf-like spathe that is ordinarily thought of as constituting the flower. To effect cross-pollenization, it is first necessary to amputate the spadix, removing the upper portion, with the staminate flowers. Pollen gathered from another spadix may then be dusted with a camel's hair brush over the pistillate flowers at the base of the amputated spadix. Of course no attempt is made to operate on the individual flower; but the group as a whole may thus readily be fertilized. As the pistillate and staminate flowers on any given spadix ripen at different times, there is no danger of self-fertilization if the operation of removing the upper part of the spadix is performed at the right time.
To a fair proportion of country folk, anything that is not obviously a pink or a rose is characterized as a lily. And in point of fact the diversity among the lilies and allied species is so great as almost to justify the wide implications given the name colloquially. A gigantic calla and a tiny trillium, for example, seem about as far removed from each other as two flowering plants can well be. And the most familiar forms of the tiger lily, which may perhaps be said to be the typical member of its tribe, assuredly bear small resemblance to either calla or trillium. Nevertheless there is a large group of lilies that bear greater or less resemblance to the typical species, having characteristics of form, no less than of arrangement of stamens and pistils, that are quite unmistakable to anyone having the slightest botanical knowledge. A large number of these may be hybridized readily, and I have personally worked with a great number of species. But while the results have in many cases been interesting, they have not been very spectacular, or very important, and it is not necessary here to go into details with regard to most of them. It will suffice to tell of two or three typical hybridizing experiments made chiefly with the native leopard lily (Lillium pardalinumn) as the pistillate parent. The extent of my experiments with the tribe may be gathered from the statement that at one time on the two Sebastopol farms I had fully five hundred thousand more or less distinct kinds of hybrid seedling lilies. About three-quarters of them were produced by pollenizing the native species just named with all the species from different parts of the world of which I could obtain specimens. I found that hybrids between the numerous species of lilies that are native to the Pacific Coast could be made with the greatest facility. Tens of thousands of seedling hybrids between the different indigenous species were produced. But, on the other hand, hybridization with the foreign lilies was found to be rather difficult, different species having seemingly diverged somewhat toward the limits of affinity. One of the most successful crosses was that made between the species known as Lilium Humboldtii and L. parryi. The former has a very large bold, thick petal, white, with large distinct spots, and it is fragrant. The other parent is a tall, slender variety, the flower being clear buttercup yellow, with very small spots or none. The cross was made with some difficulty, and the result was a lily which some connoisseurs have considered one of the most beautiful ever developed. It grows about four feet in height, and its flower is open bell-shaped, with partially curved petals, brilliantly yellow in color, without a spot or dot, and having a delightful fragrance. Another interesting cross was that between L. pardalinum and L. parvum. The hybrids of this cross sometimes produce hundreds of blossoms on a single stem, and several hundred clumps from a single bulb. Not only do they multiply with astonishing rapidity, but in size, color, and abundance of bloom they exceed either parent, although both parents are prolific bearers. The crosses of the somewhat fragrant L. parryi with L. Wash ingtoiiianum and L. pardalinuM produce bulbs having similarly extraordinary powers of multiplication, although in this regard there was a most amazing variation. Certain individuals would produce a hundred bulbs while others of the same fraternity were producing only one or two. Some of these seedlings would grow eight or ten feet in height, while here and there would be one from the same lot of seed growing only eighteen inches or two feet in height. But the most striking characteristic of these hybrids was their exquisite fragrance. Even though the seed Were grown from L. pardalinum, which is never fragrant, the hybrids having the L. Washingtonianuim cross for the other parent, were so fragrant that when massed together their perfume saturated the air, and could be distinguished, down wind, at a distance of several miles. The individual plants differed widely on close inspection as to their forms and colors, but when viewed from a distance the effect was that of a great gorgeous spread of cloth of gold. The variations in form of stem and flower among these hybrids extended also to the bulbs, some of which were flat and of varying colors, from pale rose and crimson to yellow, and others of which were compact, resembling pears or apples in form. Another striking peculiarity of the bulb was that some of them had scales that were solid, as in the Washingtonian, while in others of the same lot the scales would be divided into several separate divisions, each of which would grow a form of new bulb under proper conditions. Some of the bulbs when exposed to sunlight would turn to a brilliant crimson, while others after exposure for any length of time were white or yellow or variegated. There was similar variation as to the resistance to decay. I may add that some of the little bulbs, notably those of L. Brownii, are edible and are considered a great Christmas delicacy by the Chinese, who make most delicious stews and soups from these bulbs. I myself have eaten the bulbs of L. Brownii, grown on the Sebastopol place, and have found them to have a most delicious oyster-like flavor. The possibility of these lilies as food producers have not hitherto been given the attention they deserve. All these lilies have bitter bulbs, and they are fairly resistant to eel worms, milliped, and thrip, etc., whereas the Brownii is invariably destroyed in the second year, and can only be grown in new soils. All the true lilies finally succumb on old soils. I have tried to eliminate the bitterness through crossing but got no favorable results.
SOME WIDER HYBRIDIZATIONS
It has already been stated that the California lilies do not cross readily with the foreign species. Nevertheless I have made successful hybridizations in many cases. Among the most interesting of these crosses was one in which the so-called Lily of the Incas (Alstroemeria-not a true lily, having no bulb), of South America, was crossed with the familiar California species (L. pardalinum), already so often referred to. Of some of these hybrids I raised a large number, and they presented interesting variations. Some of them, when they bloomed, seemed almost counterparts of the South American parent except that their petals recurved like those of the California lily. Some were spotted like the California parent, and some were quite without spots. As a rule, however, these hybrids, even though producing fairly abundant foliage, did not blossom at all, and at best they were small and insignificant, and within a year or two most of them had disappeared. They seemed to produce inferior bulbs that could not withstand the winter. As further evidencing the lack of virility of these hybrids, it may be noted that all of them were dwarfs. In striking contrast to hybrids of the pardaliunum with other native lilies, none of them grew more than a foot in height and many of them not over six inches. These dwarfs were rendered all the more striking by the fact that the miniature lilies reproduced in many respects the characteristics of their South American parent. Another interesting hybridization was that effected between the pardalinum and a species of the native trillium, a plant familiar in our woods under the name of drooping night-shade. The trillium is, of course, a lily, but, like Alstroemeria, it belongs to a different genus from the leopard lily, and its strikingly different appearance has already been referred to. The hybrids produced by this strange union were dwarfs with broad, lily-like foliage, with blossoms that resembled those of the trillium-having three very broad, flat, greenish-white or yellow petals, and three narrower petals, like sepals. A plant that thus bore a close resemblance as to foliage and general appearance to the leopard lily, yet which had blossoms like those of the wake-robin (though somewhat larger and coarser) made a very striking and interesting exhibit. The species of trillium used in this cross was the common native Trillium ovatum. The hybrids, although in themselves so interesting, proved lacking in vitality, and notwithstanding my efforts all died-not, however, before I had secured photographs of the strange trillium-lily combination. Among all my experiments with the lilies, there is perhaps no other result quite as interesting as this hybridization with the trillium. Its results suggest the desirability of further experiments along similar lines. There is an almost boundless opportunity for new series of investigations with members of this very extensive group. The plants may readily be cross-fertilized by the amateur, and interesting results must follow almost as a matter of course. The plant developer who pays heed to the fragrance of his flowers as well as to their other qualities, is almost certain to produce varieties that will be appreciated. The perfume of the flower and the flavor of foods are now-a-days receiving more attention than formerly.
This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 9 Chapter 8