Memoir, Horticultural Society of New York (1902)
Hybridizing Gladiolus Species
W. Van Fleet

In the following notes the term "species" is necessarily used in the horticultural rather than the strict botanical sense. For many years, through the kindness of Herr Max Leichtlin, Baden Baden, Germany, and others, we have been enabled to receive newly collected Gladioli from Africa and Madagascar, often in advance of their botanical determination, and at once used them for breeding purposes. For convenience it may be well to divide these newcomers into groups according to their garden affinities with wel known species, and as a further preliminary it may be stated that only Summer blooming species and varieties having corms that keep well over Winter are desired by growers in this country. We have produced hybrids between the Gandavensis or psittacinus, as well as Lemoinei or purpureo-auratus sections, and such early flowering species as tristis, vinulus, trimaculatus, cuspidatus, ramosus and Gandavensis x trimaculatus bloom in August and have long-keeping corms. They increase rapidly, have attractive characteristic forms and markings, but the comparatively small size and neutral flesh tints of the blooms do not rank them among decorative Gladioli.

The largest group of new species comprises types allied to G. dracocephalus. They come under the names of Cooperi, platyphyllus and various numbered forms collected during the last six years in Swaziland, Durban and Madagascar. The most promising horticultural type cam labeled from Mt. Kilima-Noscharo, in Eastern German Africa. It is a slender but healthy grower, and has a fine spike, large hooded flowers, scarlet penciled with orange outside, and clear deep yellow inside, deepening to orange in the throat. Seedlings of this distinct form are under way, but have not yet bloomed. Platyphyllus has immense deeply ribbed foliage, looking like a vigorous young palm, before the flower stem arises, and a large corm having a hard woody covering. The flowers are rather small, red and yellow, penciled with purple, strongly hooded, with the perianth so short that the stigma and anthers protrude, a characteristic shared by other allied unnamed species recently flowered. Hybrids with large flowered garden Gladioli have little merit in the first generation, but improve later on. Already several hybrids of dracocephalus have been put in commerce by European breeders. They are not of a character to commend the type to beauty loving amateurs, being too narrow and hooded in form and blotchy in coloring. The best dracocephalus hybrids we have seen were sent out under the name of G. hybridus asperus by Herr Leichtlin. They are vigorous, well furnished plants, bearing 10 to 14 broad, well opened flowers on a strong spike. The colors vary from orange to cinnabar red, penciled all over in intricate patterns with deep or brownish red. They are harmonious and attractive in outline and coloring. Some of the newer species of this group evidently come from arid regions, as they bloom early and ripen up their corms with great promptness. Hybrids obtained from them often show the same tendency, and a useful class of early bloomers may yet be obtained from this progeny. A tall-growing form of G. platyphyllus from Swaziland has green blooms covered with pencilings of bluish purple. By crossing it with the best violet blues of the Lemoinei section we have made a start toward a "blue" class of a very distinct aspect. This form of platyphyllus is destitute of the woody corm coatings, and is of excellent constitution, having long and attractive foliage.

The psittacinus group is of great interest as the foundation of the splendid Gandavensis strain, and through it of all the fine modern garden Gladioli. We have used psittacinus very extensively, and generally obtain brilliant red and yellow blooms, a dense long spike, and a rigid upright growth. G. igneus, decoratus, and the valuable new Quartinianus are of this type. The first and last are very late bloomers, needing the shelter of glass in late Fall to perfect the blooms. Hybridizing with selected earlier blooming garden varieties lessens this tendency and imparts much beauty of coloring to the stately habit and lusty growth of this useful group. G. sulphureus or Adlami is plainly an offshoot psittacinus. It blooms early in July and has a straight spike of medium sized clear sulphur yellow flowers, sometimes having a greenish tinge. Some growers say sulphureus of the Dutch florists is different from Adlami, but corms procured under both names from various sources produce identical flowers. This yellow species or variety of psittacinus would appear a potential breeder for the much improved yellow garden sorts, yet persistent work, extending over seven years, has resulted in only two good golden yellow hybrids out of thousands of direct crosses bloomed. These are the product of Adlami x Canary bird, the latter a fine American yellow Gandavensis of rich color but crooked growth. The other seedlings all came red, often very intense, with a few creamy whites, although varieties with yellow predominating were almost exclusively used in pollinating. The two good yellows are large and fine, but of provokingly slow increase. Quartinianus hybrids, especially with the new G. cruentus section, are very promising, the tall leafy plants being furnished with large and striking blooms chiefly red and yellow.

The oppositiflorus group naturally follows, as many growers have little doubt that the original Gandavensis, known to be the parent of all our superb garden strains, was produced by a union of psittacinus with something of the oppositiflorus type, instead of with G. cardinalis, as so often claimed. We have grown many direct hybrids of psittacinus and its allies with oppositiflorus and floribundus that appeared quite identical with Gandavensis, as we have been able to procure the type, while on the other hand repeated attempts, extending over many seasons, to hybridize cardinalis with psittacinus and its allies have uniformly failed. This is the experience of more than one European investigator, and may be taken to almost conclusively settle the matter. Oppositiflorus, with its tall growth and many-flowered spikes, often opening 18 to 24 blooms almost simultaneously, together with its delicate peach-and-white tinting, seems a most promising parent for producing fine whites and light-tinted varieties of the exhibition type, but our own profuse trials, as well as the results of many contemporary breeders', show an appalling amount of chaff to very few grains of wheat. The results of the first two generations of hybridity are almost nil in a decorative sense, but the third consecutive pollenization with the best modern white and very light kinds has developed some very pretty and hopeful new varieties. The looked-for high-class pure white has not come by this means, though an almost stainless oppositiflorus was used at the beginning and rigid selection since maintained. Really clear whites have appeared from psittacinus and drachocephalus, hybridized with oppositiflorus, showing very strong pollen influence, but they have little vitality and low powers of perpetuation. Floribundus appears the more promising of the two as a parent, though inclined to transmit red coloring to its seedlings. Its hybrids are more likely to bear flowers facing one way than oppositiforus, which takes its name from the distichous or two-ranked manner in which the blooms are borne. The only other useful member of this group known to us is a new one which came labeled "narrow-leaved species from Swaziland." The corm had evidently been collected when immature, and lay dormant two years, at last producing a long spike—32 flowers—of very short and small blooms, pale lilac with feathery markings of a deeper shade. The blooms face one way and open well together. It is a very late blooming sort, but a few hybrids were secured which are now well under way. All growers of Gladioli of the Gandavensis type know there is a constant preponderance of the red varieties. The white and light colors tend to degenerate with greater or less rapidity, while the reds increase in number and maintain their vigor. So rapid and complete is the reversion in some instances as to amount to wholesale atavism. Considerable numbers of a choice Gandavensis variety have, propagated for generations in the usual manner from cormels, changed in a season so as to closely resemble the typical red and yellow Gandavensis. This seems to confirm Mendel's theory of dominant and recessive factors in all hybridizations. Taking psittacinus as the dominant, oppositiflorus acts in most instances as the recessive type, and tends rapidly to efface itself in favor of its virile partner during reproduction by seeds, and to a lesser degree during extension of a given hybrid plant by cormel or bud propagation.

Gladiolus purpureo-auratus is well known to be the foundation of the popular Lemoine and Nanceianus strains of commercial varieties and G. Papilio of the "blue" Lemoinei kinds. These latter comprise a number of attractive heliotrope and purple-blue shades in the typical hooded form of the parent. Papilio albus is a handsome slender-growing variety, reproducing itself perfectly from seed. It is very pure white in color, with a crimson purple blotch. Crossed with the best whites among the Gandavensis and Lemoinei sections it produces a few attractive and distinct new light garden forms amid a great proportion of inferior ones. We regard it as promising and will continue work among its dilute hybrids, of which we are now approaching the fourth generation.

G. saundersi
Gladiolus cruentus
Vaughan's Seed Company 1909
Princeps
Mrs Beecher

The species typified by G. Saundersi are of the first importance. Saundersi, in the hands of Herr Leichtlin, gave us the magnificent strain known in commerce as Childsii, still of the very highest commercial value, and the large-flowered, brilliantly-colored Nanceianus sections, produced by Messrs. Lemoin by crossing purpureo-auratus hybrids with the new species. Leichtlin used pollen from the finest procurable Gandavensis varieties on Saundersi, and the result is a class of gigantic, richly-colored kinds mostly of red tints, with the widely expanded blooms having a nodding upper segment. When the reverse cross is made, and ovules of Gandavensis fertilized with Saundersi pollen, the result is far less striking.This has been verified by many thousand personal results trials. G. Leichtlini is a dwarf early-blooming species, with pretty red flowers having a yellow mottled throat. It is closely allied to Saundersi and the following species, and crosses readily with both. One would consider it a promissing breeder, from the dainty aspect of its wide-open blooms, but it has in our hands proved quite disappointing. Hybrids with Gandavensis, Lemoinei and Nanceianus types, with very few exceptions, lose individuality, whether the seed or pollen is taken from the species, and are a woeflly commonplace lot. Crossed with Saundersi or cruentus, however, a beautiful and vigorous progeny results, quite intermediate in either case. They are early blooming, and being sterile are wonderfully profuse in bloom. Lemoine's Glaiëuls précoces look much like some G. Leichtlini hybrids, but it is understood that sulphureus is a parent to some of them.

Cruentus is a particularly showy species, very distinct, though allied to the preceding (Gladiolus Saundersi) both from the botanist's and gardener's standpoint. While vigorous and profuse in bloom if its requirements are satisfied, it must be considered a particularly "miffy" species for general cultivation. Though known for many years it no sooner appears in a dealer's catalogue than it is taken out for want of stock. Orders for corms of this species are filled with almost anything but the true article, and much disappointment has resulted among breeders and fanciers in consequence. It healthy corms are planted in nearly pure sand, with a stratum of peat for a root run, kept fairly moist, and the plants afforded plenty of sun, they make strong, leafy plants and bloom finely, but resent any suspicion of clay, and seldom thrive in rich garden soil.

My European correspondents report indifferent results from crossing cruentus with other species and garden varieties, the seedlings falling off from the parents in substance or coloring. This is our own experience in the main, but the first batch of hybridized seedlings yielded the truly magnificent varienty since known as G. hybridus princeps. It came from seed of cruentus x Childsii, the Childsii being, as above noted, Saundersi x Gandavensis. It is not necessary to describe Princeps further than to say it almost exactly reproduces cruentus in its scarlet-crimson coloring, with white and cream featherings in the lower segments, but the flat circular flower is expanded to six inches in diameter both ways, the plant is doubled in size in all its parts, retaining the dark green lustrous and profuse foliage, and is of a vigor of growth and virility of increase hitherto unknown in the genus. It appears to succeed wherever tested, and can be doubtless grown anywhere and in any soil. A peculiarity of cruentus in developing its flower spikes after the first buds open is fully retained. When the spike first appears it is short and blunt, looking as if only a few blooms would develop, but growth proceeds as large and perfect as the first. This progressive growth continues in water, if frequently changed, almost as perfectly as on the plant. From two to four blooms are fully expanded at the same time, thus giving a flowering period of nearly five weeks for a plot of Princeps, taking into consideration the successive side spikes and extra flowering growths sent up from strong corms. During this period, from the first of August to near the middle of September, a bed of this variety rivals in brilliancy an equal expanse of scarlet salvias.

Attempts to reproduce Princeps by repeating the original cross have always failed, but many good flowers have since resulted, some of which seem worthy of perpetuation. Some odd fawn and ash colors result when crossed with species of the psittacinus and dracocephalus types. With oppositiflorus it gives a soft pink of remarkable profusion of bloom, possibly valuable for bedding purposes. The potentialities of cruentus will not soon be exhausted, and it is likely to be frequently heard of in the future.

A few unique species remain, among which Ecklonii seems most practical. It is a little plant, growing 15 to 18 inches high, with a short spike of star-shaped flowers, dull white, profusely peppered with dark purple brown. It is delicate and likes plenty of heat, but the corms are quite large and are excellent keepers. The first hybrids with oppositiflorus and light Lemoineis yielded strong plants, with long, many flowered spikes, running into shades of wine and light purple-brown, covered inside and out with characteristic spotting of darker tints. The best of these singular hybrids, pollenized with Princeps and large-flowered garden varieties, have developed very striking large kinds with finely-shaped blooms of various pink and wine shades, with the profuse spotting well brought out. They appear well worthy of introduction as soon as sufficient stock is secured.

G. Ludwigi is an odd species of tall and very upright growth. The leaves are strongly plicate, resembling young palm fronds, and are quite hirsute, the pubescence being most strongly marked on the flower spike. The many flowers are dull salmon-pink, small and poorly opened. They are quite ventricose in form, and very late in appearing. Crossing with cruentus, the only species we could manage to bloom at the same time, has improved the form, enlarged the size, brightened the color and advanced the season of bloom, while removing most of the pubescence from the plant, which is still very upright and plicate in foliage. It is not a promising species to work from, but we hope to keep at it until real garden improvement is obtained or the successive dilute hybrids become sterile.

A most distinct and beautiful little Gladiolus species was sent us three years ago by Herr Leichtlin, whose collector found it among high cliffs in a little-known part of Madagascar. It is not larger than a Freesia in growth, and produces good-sized and elegantly formed blooms of pure bright yellow. The yellow is as good as the best Jonquil or trumpet Narcissus, and not the pallid greenish tinge usually found in the genus. It is a Winter bloomer, and our best efforts have been made to switch it around to get Summer flowers, so as to connect with yellow garden kinds. The only species we have had an opportunity to cross it with is igneus, of the psittacinus group. One viable seed was secured, which has just produced a blooming plant. No yellow coloring appeared, the wide-open blooms being quite clear salmon. It is attractive in make-up, and may be of future service, though devoid of decorative value. If the yellow Madagascar species is ever obtained in quantity it will prove a treasure for Winter blooming. The little corms resemble those of Summer-blooming kinds, and are good keepers.

It might be supposed that during 16 years of active hybridization among Gladiolus species, resulting in over 150,000 seedlings, many commercial varieties would be produced. Although we have found beautiful and promising novelties in this mass of hybrids and variety-crosses, only two so far have been thought worthy of naming and commercial introduction. One is the Cruentus-Saundersi-Gandavensis hybrid, above mentioned as Princeps. The other is a direct cross between purpureo-auratus and Saundersi, known in a limited way in the trade as Lord Fairfax. It produces a long, curving spike of Indian-red bloom, with a yellow and purple spotted throat. These are often five to seven inches across, and look like Hippeastrum blooms arranged in a Lily-of-the-Valley manner.


The Complete Book of the Gladiolus, 1953
Lee M Fairchild

About this same time Van Fleet introduced the red variety Princeps, a seedling of the species G. cruentus and a variety, Mrs. Beecher. This is variously reported as having been first listed in 1897 and 1903. It was used extensively by European hybridists after it became available and is probably the basis of the later Pfitzer scarlets and reds.