The Drama of Iris Development (chapter 3 from the World of Irises)

Continued from chapter 2 The History Of Iris Development

by Melba Hamblin

TRANSITION-DIPLOID TO TETRAPLOID

Conversion from diploidy to tetraploidy is a classic in iris history. Almost everyone has read of the excitement that stirred the iris world when 'Snow Flurry' made its debut. If we can-in fancy-go back in time when early hybridizers began crossing the small flowered Eurasian diploids with the taller, larger flowered tetraploids from the Fertile Crescent, multiplying that 'Snow Flurry' excitement again and again, and adding a measure of mystery to offset the fact that breeders of the nineteenth and early twentieth centuries were unaware of chromosomes and genes, we may be able to empathize with those who witnessed the metamorphosis that transpired with the development of 'Ambassadeur', 'Souvenir De Mme Gaudichau', 'Mme Claude Monet', 'Dominion' and other early tetraploids.

	'Snow Flurry' 1939	'Ambassadeur' 1920	'Souvenir De Mme Gaudichau' 1914	'Dominion' 1917

As Dr. Wister has related, hundreds of irises were introduced during the nineteenth century from the diploids Iris pallida and variegata and their natural or man-made progeny with the possible admixture of related species I. cengialtii, illyrica and imbricata. The potential of these diploids had been virtually exhausted when the fortuitous discovery of the Asiatic tetraploid species and the visionary persistence of hybridizers provided the stage for the Greatest Show in the Floral Kingdom.

The spectacular improvement of irises during the following era was due to the difference in chromosome number of the diploids and tetraploids. However, with few exceptions, our early hybridizers were unaware of this difference and their success in transferring the various colors and color patterns of the smaller flowered diploids to the larger flowered, self-colored purple and white tetraploids was the result of intuition and endless effort.

Although the identity of those invaluable tetraploids has never been determined, records show that I. trojana, mesopotamica, kashmiriana. cypriana. and cultivars, of these species, 'Macrantha', 'Ricardi' and 'Amas', played starring roles in developing tall bearded rises. A few garden varieties were produced by intercrossing the tetraploids, but the best results in those evolutionary years came from crossing them with the diploids of the previous century. From such crosses, occasionally, instead of the usual infertile triploid, a tetraploid with large flowers, improved form, substance and plant labits-and fully fertile-would result.

BASIC BREEDING

Modern irises are based on pioneer breeding that originated in France and England. In 1904 the Vilmorin firm introduced the first hybrids from tetraploid species: the pinkish buff, old rose bicolor 'Isoline'; bronzy lavender purple 'Tamerlan'; and the blue-violet 'Oriflamme', credited by Dykes as derivatives of I. trojana, cypriana, and Amas. From the same firm came mauve and pansy-violet 'Alcazar', the red-violet and deep velvety maroon 'Ambassadeur', and the cinnamon-buff, wine-violet blend 'Dejazet'--of unknown parentage but of great parental value. Many reds and dark purples can be traced back to the first two; 'Dejazet' is a major star in the ancestry of numerous blends.

In southern France, Denis, inspired by Foster's work, searched for a parent to bring size to his seedlings. He chose 'Ricardi', a form of I. mesopotamica, collected in Palestine by his friend, A. Ricard. Using this with forms of I. pallida he obtained the light blue-violet 'Andree Autissier' pale mauve 'Mlle. Schwartz' and bluish white 'Blanc Bleute. All played active roles in the developing drama.

Millet et Fils, another French firm, used 'Ricardi' with their light blue 'Corrida' to create 'Souvenir de Loetitia Michaud', an excellent violet self that became the pod parent of 'Gloriole'. I. cypriana x pallida rewarded them with deep bluish purple 'Souvenir De Mme Gaudichau' and from this, crossed to the light reddish 'Troost', came 'Germaine Perthuis', a deep purple bitone with fine form and size.

Ferdinand Cayeux entered the scene a few years later than his compatriots but he soon outdistanced them both in the quantity and quality of the irises he introduced. His Dykes Medal winners (10 in 10 years!) include varieties well known to fanciers and hybridizers throughout the iris world; and 'Pluie d'Or', 'Depute Nomblot', 'Jean Cayeux' and 'Madame Louis Aureau' figure prominently in the evolvement of modern irises.

Sir Michael Foster's garden was a mecca for iris lovers, and his friendliness and generosity contributed greatly to the rebirth of international iris interest. Foster's collection included tetraploids I. trojana, cypriana, Amas, and three color forms of I. kashmiriana, one of which was white (Randolph 1951a). He made innumerable interspecies crosses and is credited with being the first hybridizer to use I. cengialtii, trojana and cypriana. From the last two, used with I.pallida, he originated the important tall bearded varieties: bluish lavender 'Caterina' and the medium blue bitones, 'Lady Foster' and 'Shelford Chieftain'.

The parentage of two of Foster's important introductions, 'Kashmir White' and 'Miss Willmott', has been subject to speculation for many years. Generally it has been assumed that I. kashmiriana was one parent, with supporting evidence uncovered by Randolph when he studied Foster's original records and notebooks, preserved at the headquarters of the Linnean Society in London (Randolph 1951b).

From Foster's tetraploids George Yeld developed the medium blue bitones 'Arac' from 'Amas' x I. cypriana and 'Lord of June' from 'Amas' X unknown, and Sir Arthur Hort introduced a series of hybrids involving various combinations of the Foster collection. Crossing I. pallida and trojana gave him bluish violet 'Regan'; pallida x 'Mandraliscae', dark blue 'Miranda'; and trojana x 'Caterina', the attracfive light lavender blue 'Ann Page'.

EARLY HYBRIDS AND HYBRIDIZERS

When World War I ended, comparatively few gardeners knew of the phenomenal work of Foster and the hybridizers who had worked with the influential tetraploids. But when the worldwide distribution of the polyploids and their progeny became possible after the Armistice, it was evident that we were well into the Iris Drama that had been quietly developing for more than 30 years. The greatest hybridizer of this transitional period was Arthur J. Bliss of England who spent years experimenting with inbreeding to determine parentages of existing garden varieties. With this knowledge as his basis he was successful in creating new varieties of merit in all types of irises. His most important iris was 'Dominion' from 'Cordelia' x 'Macrantha' (synonym, 'Amas'). 'Dominion', a rich violet bitone with heavy substance and wide flaring falls of velvety texture, was hailed by many as the greatest break among the early tetraploids. Bliss sold his stock to Wallace who, with "Barnum" shrewdness, instead of introducing it at the usual price of 10 shillings, offered it in his catalog at the unheard-of price of 5 guineas-more than $25.00 in our money. The result was instant publicity. Fanciers who would not have paid 5 or 10 shillings for it put this expensive variety on their '"must have" list and quickly bought the small supply. It came to this country in 1918 to the Ohio gardens of J. D. Wareham and Mrs. Samuel Taft. Mrs. Taft had a standing order with the Wallace company for 10 plants of each new introduction. Accordingly, she received 10 plants of 'Dominion' and-much to her astonishment and dismay-a bill for $250.00 (Wister 1953).

'Dominion' (figure 1) had been in this country only a few years before its outstanding but unmentioned tendency to die out was discovered. Fortunately, Bliss and other breeders had mated it with various diploids and tetraploids, bringing us the famous 'Dominion' Race that included: 'Cardinal', a velvety red bitone; 'Bruno' (figure 1), lavender-tinted bronze standards and rich red-purple falls; Mrs. Valerie West, bronzed lavender red; and Grace Sturtevant, rich brown and violet. Dominion is one of the outstanding achievements in the iris world. There are few dark blue purples or dark red purples whose family trees do not carry its genes.

At the International Conference held in Paris (1922) Bliss's paper included several comments concerning his originations:

• 'Dominion' came from a pod with a single seed …. I am inclined to think that 'Dominion' is in some way a mutation, possibly a tetraploid like De Vries' Oenothera gigas, which is calculated to appear only once out of 900,000 seedlings …. It is worthwhile to note that exceptional flowers, showing a great advance on ~heir parents, have nearly always come from crosses that produced very few seeds, generally only one or two …. 'Bruno' came from two seeds; 'Gabriel', two seeds; 'Blue Bird', one seed; 'Patrician', one seed; 'Phyllis Bliss', one seed.

AMERICAN HYBRIDIZERS

As noted by Dr. ·Wister, Bertrand H. Farr was the first important American hybridizer. Grace Sturtevant was our next breeder of note and was among the first to study genetics and plan definite goals. One of her early objectives was to create a tall yellow that would thrive in southern California where yellows, mostly derivatives of I. variegata, were unhappy. A cross of I. pallida x 'Aurea' gave her 'Palaurea' and Afterglow. Palaurea x Celeste (almost pure pallida) produced Hope, and from Hope selfed came Shekinah, a tall light yellow that grew well from coast to coast. In 1917, Miss Sturtevant received the Massachusetts Horticultural Society's medal for Shekinah; Afterglow, a grayed lavender-yellow blend; and B. Y. Morrison, a pale lavender and deep violet bi tone.

Bruce Williamson, Indiana, was our third breeder chronologically, and perhaps first if we consider the quality of his irises and the wide range of his work. He was the first breeder in this country to work with apogons and first to give us a great bearded iris--Lent A. Williamson, a bitone with lobelia blue standards and rich purple falls. Often referred to as the American Dominion because of its quality and breeding potential, Lent A. Williamson gave origin to countless superior irises including the light mauve and buff blend, Dolly Madison; the blended red bitone, Cinnabar; and the red-purple 'Geo. J. Tribolet'.

In Nebraska the Sass brothers, Hans and Jacob, were experimenting with I. trojana, mesopotamica and 'Amas'. Of the innumerable early hybrids they developed, 'King Tut' (Hans) was one of the more significant breaks. Breeders were quick to realize its possibilities and it is in the parentage of numerous irises. Both Hans and Jacob used it extensively. By crossing it with Hans's 'Baldwin', a tall light blue named about the same time as 'King Tut', they raised seedlings in a wide range of colors. From this cross Jacob named the medium reds, 'Joycette' and 'Waconda'. Hans named 'Rameses'.

Rameses, a pinkish blend, was probably used during the 1930s and the early 1940s by more hybridizers than any other tetraploid. The irises that carry its blending legacy are legion, but in the drama of the Iris, its starring role was as a progenitor to the flamingo pinks. William Mohr of Mt. Eden, California, worked with I. cypriana, trojana and kashmiriana. However, I. mesopotamica was responsible for his best tall bearded varieties. With Juniata it gave the fine light blue 'Conquistador'; with 'Parisiana', mauve 'Balboa' and red-violet 'Esplendido'; and with 'Eldorado', a medley of colors including the medium blue 'Coronado'. Sydney B. Mitchell, Mohr's friend and collaborator, was also a distinguished California hybridizer who, like Mohr, kept accurate records and worked toward specific goals. After Mohr's death in 1923, Mitchell inherited his records and plants, and in time introduced the wondrous assortment of irises known as the Mohr-Mitchell seedlings.

Mitchell's most important work with irises was in the yellow class (Mitchell 1934). His favorite introduction was 'Alta California', " … because it gave me my greatest thrill in achievement, as it was a yellow iris without any yellow in the parentage and justified my scientific approach to the problem." Historically, probably his greatest achievement was in crossing the diploid Shekinah with 'Argentina', thereby starting a line that led to a breakthrough in the search for large, clear yellows. Marion Shull introduced several praiseworthy hybrids during the 1920s. Morning Splendor from I. trojana and Lent A. Williamson brought him fame and a gold medal from the Garden Clubs of America. Red-toned Morning Splendor was a valuable parent and appears in numerous pedigrees including those of Paul Cook's reds and his rose-violet 'Dreamcastle', a parent of 'Melodrama'.

ACCELERATION BY ORGANIZATIONS

With the founding of the American Iris Society in 1920 and the British Iris Society in 1922, the pace of transition from diploidy to tetraploidy quickened. Iris societies were formed in other countries as glorious new colors and refinement aroused interest in those who had resisted the charms of the Rainbow Goddess when, during the diploid era, she had been clothed with less brilliance. As methods of communication and transportation advanced, the exchange of plants and information, and travel to far away places, were facilitated. Currently, participation in iris affairs is enjoyed on an international scale.

The Iris fraternity that circles the world is an everlasting memorial to the early hybridizers who devoted their lives to the Drama of Development.

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"The World of Irises" continues with chapter 4 Development of the Tall-bearded Irises

Chapter 3 was continued from chapter 2 The History Of Iris Development

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-- BobPries - 2015-12-08