OF CROSS-BREEDING AMONG FLORISTS' FLOWERS
ANY new plant which the cross-breeder brings into the world, and which was never in the world before, may be called, figuratively, a new creation. And if you ask him how he knows that his new plant has not been in the world previously—at least, not since the flood—he will give you as the reason, that the remains of the old world have not yet brought to light any fossil kind or kinds of plants which could by their union produce such a form as his new seedling. That, then, forma the text for disputes, without end, about the origin of species, and the races of plants, the extinct vegetation before the flood, the ways of clothing the earth alter the flood with forms of vegetation differing from the extinct races, and differently disposed as to countries and climate's.
Call the seedlings what they will, I shall never call in question aught on the subject which cannot be proved or disproved by direct experiment. One fair experiment is worth all that the whole weight of the opinions in Europe could place in the scale against it; and as to wrangling about things which cannot be proved by direct experiment, it is not of the slightest use that I can see.
My limited experience has proved beyond the possibility of a doubt, that soil, or the different kinds of soil, have a mighty influence on the variegation of seedlings. Some of the discussions on the subject last summer supposed a chemical origin rather than a diseased constitution to such variegation in plants. Punch being the healthiest and the best-known kind to me of all the Geraniums, as far as its genealogy went, I took to it once again to see if it would turn out seedlings as it has done in former years on my present soil. Punch is only at home on the chalk formation. Give it a chalky soil on a chalk bottom, and cross it by what you please from the variegated section, the seedlings will all come quite green, and no variegation in any one of them. I often said how true to kind so many of the seedlings of Punch, by its own pollen, would come.
Well, last summer, as a last resource, I crossed many flowers of Punch with the healthiest of my stock of seedlings, meaning those most free from variegation, and out of two hundred seedlings from that cross now before my window, nineteen out of every twenty of them are blotched and speckled as if they would be all variegated. What, then, can, or could induce this tendency to variegation, unless it be the difference of soil? By its own pollen all seedlings of Punch in this garden come without a speck of white, but they vary from the parent very much, and not one in fifty of them is like it; whereas on the chalk Punch is all but a botanical species, reproducing itself at the rate of from 70 to 80 per cent.
You are not, therefore, to suppose that you can obtain the same results from crossing a flower of which you read in books, by merely doing what some one else did before you. But it is of much consequence to save you time and trouble to know what has been done by crossing before your day: hence the reason for this rapid sketch of the biography of crossed plants, which you now can see is to be written, without favouring this or that opinion, or anything else which cannot be proved by pollen.
Then, in the order of time, the Rhododendron was the next subject for hybridising; and it was soon discovered that the genera Azalea and Rhodora could not be held apart from Rhododendron, as they were capable of intermixing.
The Pelargoniums were as early, if not earlier, crossed than the Rhododendron; and there was this marked difference in the seedlings of the two great families—those of the Pelargonium were, most of them, barren plants, or mules as they were called, after a turn or two at crossing them; whereas those from the various sections of Rhododendrons were all but fertile to the end of many generations. It was from that disposition in the Pelargonium that the first idea of mules took its rise, and found favour with those who handled them.
In the Crinum and other sections of the great Amaryllid order were also found some barren seedlings from crossing, but not nearly to the same extent as in Pelargonium, and the inference which obtained in respect of them was, that the cause of barrenness was owing to the difference of the constitution of the two parents, and not from the dissimilarity in their looks, or their genealogy. That inference has not yet been proved either way by experiments, and is a subject well worthy the care and attention of cross-breeders, or, I should rather say, hybridisers, for it is only by the union of distinct wild kinds that the doctrine could be proved to be right or wrong.
Then, to understand how a difference of constitution in any two species of plants exists, you have only to suppose one of them to be a marsh or water plant, and the other to be the inhabitant of some dry region. Or, to come nearer home, take any of the recent Sikkim Rhododendrons which Dr. Hooker discovered growing like Mistletoes in a dropping climate, and cross it with some dry alpine Rhododendron or Azalea, and if there is any truth in the doctrine of constitutional discrepancies, the seedlings from that union should exhibit a large percentage of barren plants, or mules, if you like it better.
All that is practically known about the pollen influence of Camellias is this, that one often finds a stray anther and stamen in the most double flower, and that that pollen is better, or will give a better result than that from a half-double flower. But, as in all other cases of breeding in-and-in, I suspect the influence of good cultivation goes farther than that of the pollen in every instance, although some of our best florists believe their "hybridising" is the main element of success; thus confounding two things which are essentially quite different. The province of the florist being the improvement of races, that of the hybridiser the formation of new races to be afterwards improved.
Linaria, Pentstemon, and Calceolaria were the next genera that were crossed. But Verbena melindris, the first of the scarlet race, was introduced five years before the elders of the Calceolarias, Verbena Tweediana and teucrioides soon followed; but we never had any distinct hybrid Verbenas from their union, or at least not more dissimilar than seedlings which may be had now from one pod. Cultivation and not the pollen has certainly been the making of all our present race of Verbenas. There are many things more simple than crossing Verbenas, and I believe few people attempt it in these days. The breeding in-and-in gives us as many mules now in Verbenas; and Verbenas not cross-bred at all, will give more mules from one truss than ever the Pelargonium had given, on which the doctrine of muling was founded.
The old Pentstemon pulchellum was the first of them that were crossed, and a still older one and a very dissimilar kind, called angustifolium was the one by which pulchellum took. The seedlings were very fertile.
Calceolaria made an uncommon sensation at first among all the crossers, from the fact that a stemless herbaceous kind whose leaves even died down in the winter, could cross or be crossed by a shrubby kind, or one with a woody stem. I recollect very well that the doctrine of botanical diversity did not then hold up the hypotheses of muling from such a cause. No seedlings could be more fertile in repeated generations than those which were obtained from such very dissimilar parents. But the doctrine of constitutional conformity was never more near to the truth than in that race. All the original Calceolarias, with all their disparity of looks, had but one uniform constitutional tendency, preferring a moist cold climate, and a degree of shade from the direct rays of the sun which we did not anticipate from what we then knew of the climate of the land of their birth. But it had been a problem to this very season among crossers, whence the self plain flowers of a whole race of plants took to sporting into spotted flowers from the very first. The Messrs. Veitch solved that problem last summer, by introducing a sweet-scented Calceolaria of the arachnoides section with spotted flowers direct from the locality of the former race. The probability is, therefore, that our supposed species in 1830, 1831, and 1832, were mere seminal varieties in a wild state. At all events the new spotted flower might well be the father of a section of our seedlings in 1832-3.
No two plants could be more dissimilar in their appearance to a gardener or to a botanist than Cereus, or Cactus speciosissimus, and the whipcord Cactus flagelliformis, or both of them from the flat-stemmed kinds; but from their union I never yet detected a single barren seedling. Like the Calceolaria, their nature or constitution was exactly alike, and as opposite to Calceolaria as night and day. Yet they went to uphold the doctrine that similarity of constitution will overrule all other tendencies in its effects on cross-seedlings, and that all such will be fertile or very nearly so, not one in five hundred of the seedlings being otherwise.
|*Gardeners' Magazine, June 1835, p. 326, mentions "Hybrid Gloxinia caulescens (fertilised with the pollen of Sinningia guttata), from W. Gordon, Esq."
Gardeners' Magazine, July 1836, p. 380, has "hybrid Gloxinia (between G. speciosa and Sinningia guttata), raised by W. Gordon, Esq."
Perhaps Beaton, who was gardener to Gordon at the time, was the "hybridiser not far off".
In 1831 Limmingia [Sinningia] broke down botanically by the union of Gloxinia speciosa with the pollen of Limmingia guttata, producing the true hybrid Gloxinia glaucescens,* the first of that race now so gay and so very numerous. Glaucescens was thus the head of a new section of Gloxinia, by a hybridiser not far off, and the cross-breeders brought it by crossing in-and-in to what it is, and, as often happens, the new race sported into a newer one, the upright Fiffiana, which upright race is now the more favourite of the two. Speaking as a gardener, I do not see a single point in the generic character given of Achimenes, Gesneras, and all the eras into which continental writers have attempted to raise the various sections of them into the importance of genera proper—I say I do not see that any of these distinctions put together can uphold them from being one genus for all the purposes of the hybridiser; and when they are united again by his art there will be many new sections to improve; and every one of them, if I am not much mistaken, will uphold the doctrine of fertility in cross seedlings, owing to the constitutional similarity of the parent kinds. No family ever agreed more in their nature than does that long section of the family of Gesnerads.
As early as the period I am on now—that immediately succeeding 1830, a small white Gourd from Mexico, named Cucumis osmocarpus, with an egg-shaped fruit, was fertilised by the pollen of a cultivated Melon. The seedling produced a red fruit twice the natural size. The crossing of Melons with wild Cucurbits has been lately authenticated by M. Naudin, of Paris; and the Royal Horticultural Society have agreed, or their Council have agreed for them, that there shall be a competition next October at South Kensington for all sorts and sizes of Gourds, Pocket Melons, Snakes, Squash, and Pumpkins. That indeed was a very good move and a wise resolve. The next turn will be to select parents from these exhibitions for a new fancy set of such "fruit," to vie with illustrated-leaved Begonias, and to hang down from the rafters of the orchard-house until the day before the Show. Thirty years seem now a short period in the history of new races of plants, and in softening down of prejudices and presumptions arrived at from insufficient materials to prove a better, or at least a more practical result.
|*Such is the state of inglorious confusion into which modern botanists have brought things by their silly antics, that when Mr. Tweedie sent home the purple variety, Dr. Hooker called it Salpiglossis integrifolia; Professor Don, Nierembergia phoenicia; and Dr. Lindley, Petunia violacea. Yet these are the people who pretend to teach the uninitiated how to know plants! — Glenny, 1850.|
The coloured Petunias came in after the white at that period—1830. Petunia phoenicea* was the first of them, and bloomed first in Ireland that year; and in 1831 it was first seen in bloom on the west side of Manchester, at Lower Broughton in a stove—I saw it there then. Well, what was the difference between Petunia, Nierembergia, Salpiglossis, and Nicotiana? or is there much difference between them yet?—such, I mean, as should be a bar to their union. But you ought to have lived at that period to know which was which, and which was the likeliest thing that should happen but did not yet come to pass. A good deal of dog Latin was wasted in the different views of that relationship; but the Fuchsias coming in directly afterwards, or perhaps before the heated blood in that contest had time to flow and return as does the hot-water system, the thing was soon lost sight of, save in the instance of the pure and unadulterated Petunia, of which we know not the end just yet.
But the Fuchsias were surely in before the time stated, and so they were; but what were they? They were neither parasols nor parachutes, it is true; but, such as they were, some say we have not yet seen their betters. But biography is barred from predilections, or should be, and I say nought about it; but it was full 1836 before ever a cross Fuchsia was in the market. I offered one that summer to Mr. John Henderson, then of the Pine Apple Nursery, and he told me there were several curious ones coming out the following year. Fulgens came by Hungerford Market in a dried state from Mexico that summer; and Mr. Standish made his first fortune out of the next on the list of introduced Fuchsias. From Gracilis and to Virgata of that day—to say nothing of Coccinea the mother of the family—to Minnie Banks and to Comet, which were shown to us of the Floral Committee last autumn twelvemonths, and to Mr. Smith's Mammoth double Fuchsia sent to us since then—I say, Look from Gracilis and Virgata to Minnie Banks and Comet, and from Coccinea to Smith's Mammoth, and say or see how much or how little we owe to the florists. D. BEATON.