Shirley Poppies
Rev. W. Wilks
Quoted in American Gardening, May 1889

"In the summer, I think of 1879 or 1880, I noticed in a wilderness corner of my garden, among a patch of field poppies, one bloom with a narrow white edge. I marked it with a bit of wood, and saved the seed capsule. The seed was sown the next year, and I obtained varieties with deeper white edges, and some of a paler scarlet color. Of these I marked and kept the best. The next year the flowers got still paler colors and wider white edges. In 1883 I began to see that the presence of black, either at the base of the petals, or in the stamens was a great disfigurement: I therefore pulled and destroyed every plant having black in it and in order to get black out of the strain I used to get up before the bees were about (4 A.M.); and have continued this work of selecting the most beautiful flowers for seed, and have ruthlessly destroyed all plants which have showed even a symptom of black, however lovely they might otherwise be. This absence of black blood it is which gives my strain of poppies their wonderfully light, bright tissue-like appearance, and constitutes the whole and sole merit of the strain. I now get very few rogues, but still every year one or two will run back to the old black blood, and nothing but patient perseverance in destroying them will keep the strain pure.

"The colors go from absolutely white with yellowish stamens through pink of all shades to glowing scarlet—but a scarlet without black. Some are red with white edges, others white with red edges, and a few come veined and streaked from the center towards the edges. I am now trying to increase the proportion of these varied and flaked varieties, but my great ambition is some day to get a yellow Papaver Rhaeas. A pure white P. Rhaeas was found last year wild in a cornfield near Lowestoft. I have tried hybridizing with yellow nudicaule, but hitherto with I think no success. I say I think, because I obtained last year some distinct salmon colored ones, and this may be due to yellow nudicaule influence, but I think it is not. I saved all the seed I could of these salmon shades, and this year I hope to have the color more decided."

Rev. W. Wilks
Quoted in The Garden, September 19, 1903

"In 1880 I noticed, in a waste corner of my garden abutting on the field, a patch of the common wild field Poppy (Papaver Rhaeas), one solitary flower of which had a very narrow edge of white. This one flower I marked and saved the seed of it alone. Next year, out of perhaps 200 plants, I had four or five on which all the flowers were edged. The best of these were marked and the seed saved, and so for several years, the flowers all the while getting a larger infusion of white to tone down the red until they arrived at quite pale pink, and one plant absolutely pure white. I then set myself to change the black central portions of the flowers from black to yellow or white, and have at last fixed a strain with petals varying in colour from the brightest scarlet to pure white, with all shades of pink between and all varieties of flakes and edged flowers also, but all having yellow or white stamens, anthers, and pollen, and a white base .... My ideal is to get a yellow P. Rhaeas, and I have already obtained many distinct shades of salmon. The Shirley Poppies have thus been obtained simply by selection and elimination. By 'selection' I mean the saving seed only from selected flowers, and by 'elimination' the instant and total eradication of any plant that bears inferior flowers .... Let it be noticed that the Shirley Poppies (1) are single; (2) always have a white base, with (3) yellow or white stamens, anthers, or pollen; (4) never have the smallest particle of black about them.

Double Poppies and Poppies with black centres may be greatly admired, but they are not Shirley Poppies. It is rather interesting to reflect that the gardens of the whole world—rich man's and poor man's alike—are to-day furnished with Poppies which are the direct descendants of one single capsule of seed raised in the garden of Shirley Vicarage so lately as August, 1880. Poppy seed should be sown in the autumn or in the spring, sowing very thinly because the seed is small, and thinning out the seedlings to fully 6 inches apart. Fine flowers in abundance and over a long season can never be expected unless the seed is sown thinly, the seedlings well thinned out, and the dying flowers picked off to prevent seed forming and weakening the plant."

Luther Burbank: His Methods and Discoveries (1914)
Bringing forth an entirely new color
Luther Burbank


FOR some reason blue is not a favorite color among flowers. There are notable and conspicuous exceptions, of course, but for every species of blue flower in nature there are hundreds of flowers that are yellow, or red, or white. Presumably the color blue does not attract the eye of the insect so strikingly as do the other primary colors. Flowers are not green for the obvious reason that, since leaves in general are green, flowers of that color would blend with the foliage, and thus defeat the primal purpose of the floral envelope. And, no doubt, blue is a color nearer to green in its hue or general aspect than are the reds and yellows. So it is perhaps not surprising that natural selection has weeded out the blue flowers and given us an abundance of red and yellow and white ones. Of course, there may be some underlying reason associated with the chemical character of the different pigments that helps to account for the relative scarcity of blue flowers. But, as to this, no one at present has any definite knowledge, for the chemistry of the pigments, and the underlying differences between the pigments of different colors, in the petals of flowers are very little understood. But, whatever the explanation, the fact of the scarcity of blue flowers is patent enough. Where a flower has adopted the blue pigment, it may hold to it tenaciously. But, on the other hand, there are thousands of blossoms that show great variation in color, ranging through the various tones of scarlet and crimson and pink and orange and yellow, apparently quite without discrimination, yet avoiding blues of every type.


Conspicuous among the flowers that show this wide range of variation in color, and yet never by any chance have been known to produce a blue flower in the state of nature, is the familiar Poppy. So the production of a blue poppy in my gardens, through a long series of selective experiments, may be considered one of the most striking of the minor plant developments accomplished there. There is no record of a true blue poppy ever having been produced elsewhere. The blue poppies bloom toward the last of May or early in June each year, furnishing a spectacle that never fails to excite the interest of visiting florists. The story of the production of the blue poppy is a comparatively simple one as to its chief outlines. That is to say, the work that was directed exclusively to the production of a flower with this color was carried out without any complications of hybridizing, solely as a problem in selection. A measure of success was attained in the course of five or six years after the problem had definitely presented itself. But, on the other hand, it should be explained that the specific idea of developing a blue poppy came only as a sequel to a long series of very arduous experiments in selective breeding through which the ancestral stock that finally produces the blue poppy had been developed. And it is more than probable that the preliminary experiments, although aimed at quite different purposes, were absolutely essential to the segregation of hereditary factors in the plants of my poppy colony that made possible the final development the the flower with the anomalous color. Therefore, it will be necessary, as preliminary to a specific account of the quest of the blue poppy itself, to give somewhat in detail the story of the development of the ancestral strains of poppies of varied but more usual colors.


The poppy from which the blue flower was developed is of the variety known as the Shirley poppy. This is one of the most interesting and beautiful varieties of the species Papaver Rhoeas, the corn poppy of Europe. The peculiarity of the Shirley in which it differs from the wild form of field poppy is that it varies in color from the original red to a pale pink and even to a pure white; and that the original black central portion of the flower has been changed to yellow or white. The last-named characters are the distinctive ones. The true Shirleys never have the smallest particle of black about them. They may be scarlet or pink or white or variously flecked. But they have no black about them, and they were never yellow, until pale yellow and pale orange shades have recently arisen. This beautiful variety gains enhanced interest when we learn that it was developed as recently as about the year 1880, in the garden of an English clergyman, the Rev. W. Wilks, through a series of selective experiments of precisely the character so often illustrated in the course of our present studies. It appears that Mr. Wilks discovered in a field of the corn poppy of the usual scarlet color, a solitary flower that had a very narrow edge of white. He marked this flower, saved the seed of it, and the next year carefully watched the seedlings. Out of perhaps two hundred he found four or five on which all the flowers were edged with white. The best of these were marked, and their seed were selected from in turn. In successive years a large proportion of the flowers gained an increasing proportion of white to tone down the red, until they arrived at a quite pale pink, and finally one plant was found that was pure white. The attempt was then made by similar selection to change the black central portion of the flower to yellow or white, and in due course this also was accomplished. The new strain being fixed by selection, the Shirley poppy, which has come to be one of the most popular of flowers, was given to the world. It appears, then, that the Shirley poppy is a variety that has been specially selected within comparatively recent years, with an eye to the one problem of color modification. It therefore represents a strain of plants in which there is a curious mingling of hereditary factors for color. It is a fixed variety, at once recognizable, yet the different flowers that resemble each other to the point of approximate identity as to form and botanical features may be scarlet or pink or white or variegated, and all these colors being be represented in the plants grown from a single lot of seed, and sometimes in a single individual flower. Even as to the matter of the black center which characterizes the original corn poppy. the Shirley shows a tendency to reversion. Now and again flowers appear that have black spots at the base of the petals. These, however, are rigidly excluded by the florists in selecting seed. Other marks of tendency to variation in the Shirley are the uncertain length of the stem, which may be very short or very long, and a propensity to doubling of the petals, which is regarded as a defect. Moreover, there is sometimes manifested a tendency to a crimson hue that is regarded as reversional, and has to be eliminated by the careful flower grower.


All these marks of a tendency to variation, together with a history of the development of the flower, marked the Shirley as a plan I suitable for further experimentation. So about twenty years ago, at a time when the Shirley was a comparatively new flower, I commenced a series of experiments with this variety, securing seed from every available source. I was somewhat astonished and disappointed to find that, in spite of the diversified color scheme of this flower, there was a very striking uniformity among the plants produced from various lots of seed. Everywhere there was a strong tendency to revert to the original scarlet color, but otherwise the colors were relatively fixed. Attention was chiefly attracted to the form of the petals, however, which seemed rather lacking in gracefulness, being too flat and without character. With the thought of modifying the petal and thus beautifying the flower, I commenced the most rigid selection, choosing the first year only four or five plants out of many thousands, and from the progeny of these reselecting from season to season. I chose the flowers that showed the lighter shades of scarlet, crimson, and pink, and those that were altogether white. Attention was given also to the selection of large flowers, and in particular lo those that had the most delicate petals, but firmness of texture and any suggestion of waviness was joyfully welcomed. For many years I kept up this selection, raising large quantities of poppies, and having the aid of four or five men in scrutinizing all the flowers in the field for an hour or two each morning during the blooming time, that no specimens showing favorable variation should be overlooked. At first the progress was very slow. It was easy to find specimens that were semi-double and those that showed the black spots. But there was very slight tendency to crimping of the petals. As usual in such cases, however, there came a time when progress seemed much more rapid. Thence forward the work was encouraging and full of interest, and in a few years more a most beautiful strain of poppies had been produced which presented almost in ideal combination the various qualities for which I had been selecting. Those that were not pure white showed an astonishing variety and a beautiful blending of the more delicate shades of red and pink. The plants were graceful in form and of uniform height, and, most important of all, the petals of the flowers were of the thinness and almost of the texture of tissue paper, yet of firm texture, and artistically waved and crinkled, in strong contrast with the smooth petals of the original varieties. This plant was introduced through a prominent seedsman as an "Improved Santa Rosa Strain of the Shirley Poppy." The modifications are so striking that various horticulturists have suggested that the plant is entitled to rank as a new variety. But I preferred to recognize the variety from which the new plant had been developed by retaining its name.


It has repeatedly been observed that no flower or fruit is or can be developed beyond possibility of further improvement. However closely a new form may approximate the ideal at which the plant developer aimed there are always variations that suggest new possibilities that perhaps were not contemplated at the outset of the experiment. And the improved Shirley poppy was no exception to this rule. As work continued with the new flower, the form of its petals modified until they were exquisitely delicate, and its colors blended until the most artistic and delicate shades were predominant, attention was attracted one day to a specimen growing among the thousands that revealed a color a shade different from any other previously seen. On inspecting this flower I seemed to detect, Underlying the normal color, a smokiness suggestive of a half-concealed blue pigmentation. Naturally this was carefully guarded and the seeds of this plant preserved and sowed by themselves the following season to make the basis of a quite different series of selective experiments. The history of this new colony duplicated that of other groups of plants undergoing selection. Year by year I found an increasing proportion of flowers with the smoky hue, and always among these a few that revealed the obscure blue pigment a little more clearly. Finally, after several years of selection, I had a strain in which about one-third of the plants bore flowers of various shades of blue, some smoky or seemingly mixed with black pigment, and others with fairly clear, if not very bright, blue color. The few flowers that were pure blues were naturally selected to continue the experiment. But their seedlings for the most part failed to reproduce the color. Selecting year by year, however, among the individuals that produced flowers of the purest blue, the strain was gradually fixed until each year a plot of poppies appeared that, seen from a little distance, presented the aspect of uniform blueness. This, of course, is the patch referred to as exciting the astonished comment of florists that visit my grounds at Santa Rosa about the first of June each season. On closer inspection of the plot of blue flowers, it will be found that there are still a good many specimens that tend to revert lo the more familiar colors. But the effort to establish the blue variety as a fixed type through inbreeding and selection is still under way, and success is assured. Were the poppy a plant that is propagated by root cuttings or any other of the common modes of division, the blue variety would long since have been given to the world. But as it is necessary with this plant to develop the variety until it will breed true from seed, I have been obliged to continue the experiment at least ten years longer than would otherwise have been necessary. Now, however, it may fairly be said that the experiment has approached completion. The blue poppy is an accomplished fact. Its production constitutes one of the most striking color modifications hitherto made through artificial selection.


So far as is known, there was never an ancestor of the Shirley poppy that was blue. So here we have an illustration of an experiment that is radically different from any that we hitherto have had occasion to examine. We may suppose, to be sure, that the condition of blue pigment is one that occurred in some very remote ancestor of the new poppy. Otherwise we could not account for the presence of the hereditary factors of blue pigmentation; and obviously it is not to be supposed that our experiment in selection resulted in the creation of new hereditary factors. But the time at which any ancestor of the poppies bore blue flowers must have been very remote indeed, because no poppy either of the species directly in question or any other species has ever been found anywhere in the world that has a flower of blue color. So, as just suggested, the bringing out of this color constitutes a development of radically different character from the mere modification of color of a flower within the range of the color scheme of a species, or of allied species, or even of allied genera. The development of a Shirley poppy that is yellow, for example, which was a second task that a German experimenter set himself, would be comparatively easy, because yellow is a more common color with members of the poppy family, and a tinge of yellow is not unusual. I have myself developed and introduced strains of Shirley poppies of salmon or deep yellowish pink color. These include various shades of salmon and light scarlet, but with no trace of crimson or of darker colors of any kind. This flower, which had been selected also for size and crimping of petals and gracefulness, as well as for color, was introduced under the name of 'Burbank's Sunset Shades of Shirley Poppies.' But I mention this new variety only to point the contrast. No such amount of work was involved in its production as that which attended the production of the blue poppy, because yellow pigments are in the heredity of the poppies in general, and must have been manifested among ancestors of any given strain of poppy within relatively recent times. The affinity between the yellow and red, for example, in the case of the poppy, is clearly enough demonstrated in the experiment, outlined in an earlier chapter, in which I developed a race of crimson California poppies (Eschscholzia), the parent species being, as is well-known, bright yellow in color. It will be recalled that the new crimson flower was developed by selection through successive generations from a specimen that showed a little line of crimson, like a streak or thread of another color, lengthwise of a single petal. California poppies of various other colors were developed in the same way, but there were no blue ones among them. In the case of these California poppies, then, the relative ease with which the flowers were changed from yellow to crimson would seem to suggest that the latter color lies but slightly submerged, if the expression be permitted, in the hereditary stream, ready to come to the surface if the thin overlaying current of yellow can be removed. Another illustration of the linking of yellow and crimson in the hereditary scheme of the poppies is given by an experiment in which I crossed two distinct species of poppy, one having flowers of pale yellow, the other pure white. The hybrids without exception bore flowers of a clear crimson color. There was not a white one nor a yellow one among them. Another interesting color modification in the case of the poppy was that which produced the so-called silver lining poppy. In this case I discovered a flower in which there was a white line between the black center and the crimson petal. This line was widened by selection until the petal was white with black center, the white extending just over the outer edge of the petal, the rest of the back of the flower being crimson.

It may be interesting to recall in this connection a series of experiments in which the only true California poppy (Papaver Californica) was modified by selection, working with a five petaled sport, until a variety was produced that had six.

CybeRose Note: Wilk's discussion was written towards the end of the 1889 or earlier. The "long process" was therefore completed in 9 years or less. The story doesn't end here, though. Luther Burbank took up the Shirley Poppies with an eye to further improvement. He straightened and stiffened the stems, and made the petals wavy. Along the way he found occasional seedlings with streaks or blotches of black—the deep violet pigment that Wilks had bred out. He then found a pink seedling with an underlying smokiness, which he developed into a pale blue strain.

Burbank was not able to make the blue strain perfectly true-breeding. Many were distinctly blue, while others tended to grey, or reverted to the more common colors. He discussed these results in 1914, just 34 years after Wilks' original selection. This may seem like a long time for a breeding project, but considering the amount of variation that came from a single flower, we must think again about how long it takes for evolution to produce new forms. Burbank reported similar results with the California poppy, Eschscholtzia californica. He started with a single plant that had a thin red line on one of its golden petals. From nearly a thousand seedlings, 4 or 5 duplicated the red line—one with the line slightly broadened. With each generation the red increased until a solid crimson flower was produced. This, in turn, gave rise to other variations, including the Purple Gleam strain, the only type I have grown. The Escholtzia project was rather different from the Shirley Poppies, in that colors were added rather than eliminated and rearranged. However, the wild Escholtzia must carry genes for red pigment, though their expression is normally suppressed. The fact that the Shirleys occasionally reverted suggests that Wilks was working to suppress rather than eliminate the red and violet pigments.

CybeRose, July 18, 2014: A grey Shirley poppy in my garden—

And another from the same packet of seeds with smokey-red flowers