Development of Miniature Tall-bearded Irises (under construction)

From the "The World of Irises" Chapter 5 by Jean G. Witt © 1978 AIS

MINIATURE TALL BEARDED IRISES

The Miniature Tall Bearded series is the only one of the four median classes concerned with irises primarily diploid in origin. Though they share some of the same ancestors, the miniatures were bypassed by the infusion of genes from Near Eastern species that led to the development of the modern tall beardeds. Their small flowers and delicate stems have, in fact, been selected in deliberate opposition to the prevalent trend toward increased size. Thus they have more in common with grandmother's "flags" of the 1870s than with the very large heavily ruffled tall bearded irises of the 1970s. Although they fall in approximately the same height range, miniature tall beardeds are separated from the intermediates by a later bloom season and from both intermediates and border beardeds by smaller flowers and greater profusion of slender stems.

Optimum flower size for the class is approximately 8 cm (3 inches) in diameter, and optimum stem height about 55 cm (21 inches). Flower form tends toward the flaring and semiflaring, tailored to lightly ruffled; ruffling heavy enough to detract from the airy poise of the flowers is discouraged. Foliage is restrained, seldom over 25 mm (1 inch) wide and about two-thirds the height of the stem. Many varieties have the additional bonus of purple leaf bases. No mere concession to nostalgia, miniatures are justly popular with today's gardeners; their role extends far beyond their primary use in flower arrangements. They add variety to an iris collection and their small rhizomes and tight, floriferous clumps are a decided asset in the city garden's limited space. They are useful for edging beds of taller plants, and attractive as single clumps tucked against rocks in large -scale rock gardens. Considered less exacting in their requirements than tall beardeds, they thrive without pampering under average garden conditions. Fertilizer should be applied sparingly; experience in convention plantings has shown that amounts suitable for tall beardeds can force the miniatures completely out of size.

HISTORY

This class received its original name, Table Irises, from Ethel Peckham (1929) who with the Williamsons of Longfield Iris Farm in Indiana, selected the initial group of varieties from "runts" that appeared in tall bearded seedling rows, recognizing their potential as cut flowers. 'Siskin', 'Pewee' and 'Kinglet' were registered in 1934, 'Chewink' in 1937, 'Daystar' in 1941, 'Widget' in 1943 and 'Nambe' in 1946. Little is known of their ancestry (White 1955) since Williamson employed mixed pollen. At that time the transition of the tall beardeds from diploid to tetraploid was still in progress, and most of the varieties used, according to Mary Williamson, were old favorites such as 'Juniata', 'Shekinah', and 'Archeveque'. These first table irises had apparently inherited a preponderance of traits from the smaller diploid species. I. variegata set the prevailing colors and plant style while I. cengialti contributed an occasional smooth blue flower. A few additional varieties, such as Bliss's 'Tom Tit', Sturtevant's 'Tid Bit', Richer's 'Blue Mouse' and Auten's 'Two for Tea' qualified for the new category. At least one breeder, former AIS registrar Charles Gersdorff, worked diligently at the breeding of smaller irises, totally without impact; unfortunately, the trend of the times was toward larger types. Table irises languished until the early 1950s, when in the rush of diversification, interest was revived under the leadership of Alice White of Hemet, California. Reclassified as miniature tall bearded to emphasize their garden as well as decorative uses, they became one of the divisions of median irises; the two terms, miniature tall or table irises, are used interchangeably today. A small but dedicated group of breeders and collectors, joined through round robins, supports the continuing development of the class.

The middle 1950s were devoted to locating and distributing the older table iris varieties and to searching historical collections for possible additions to the class. A varietal checklist first assembled and published in 1966, is periodically updated. Stem and flower measurements of typical table irises from various parts of the country confirmed the suitability of the proportions for the class as Miss Williamson had given them to Mrs. White (White 1955). Flower size was further defined as width plus height equaling 15 cm (6 inches) and stem heights were extended to correspond to intermediate and border bearded classes. Limits are currently set at 70 cm (27 inches); however, stems taller than 65 cm (25 inches) are really too tall for a flower only 9 cm (3.5 inches) wide. Diameter for the curving, well-branched, slender stems was set at 3-5 mm (1/8-3/16 inches) directly under the flower buds, gradually increasing to about 12 mm (5/8 inch) at the ground line. Since actual measurements can vary from climate to climate across the country, it was determined that the ideal plant should be no smaller than 'Pewee' and no larger than 'Widget' (figure 1), as locally grown. Historical collections yielded few varieties that conformed to the specifications, but provided many potential parents in the diploid border bearded range. Following the Randolphs' trips to Europe in the 1950s and 1960s (Randolph 1966), additional small species became available; and these two groups, together with the nucleus of Williamson table irises, form the foundation of today's breeding stock.

HYBRIDIZING

Breeding for new varieties progressed slowly at first because seed set was low among the older things, and germination poor. With the introduction of the first new named miniature tall beardeds, the program gained momentum. Today most breeders are working with several generations of their own seedlings, pedigrees have become increasingly complex, and the improvements in the class are obvious. At the outset it was feared that the task of breeding a dainty plant to conform to strict dimensions of flower size and stem diameter would be difficult. However, this has not been the case. Plants of the proper size are fairly easy to obtain. Improvements in flower form, too, have appeared quite rapidly. In one or two generations the tucked, twisted petals of early table irises have been replaced with slightly ruffled flowers of increased width. Narrow, lanky falls have given way to shorter, rounder, types; yesterday's gapping standards now rise erect and arched. By 1968 enough new varieties had been introduced to warrant the activating of the Williamson-White Award, honoring E. B. Williamson, who introduced the first irises of this type, and Alice White whose efforts assured the class its present status. Williamson's small white 'Pewee' became the first winner of the award.

CHALLENGE FOR BREEDERS

Improvement of flower color by increasing its intensity, and extending the range of colors and patterns, remain the chief challenge for table iris breeders of the 1970s. Brilliance is not lacking in the parent diploid border iris stock-many of the plicatas and bicolors are excellent. However, easing the smooth satiny blues of I. cengialti and I. illyrica past the I. variegata yellows is proving tricky. The smaller tangerine bearded border irises have yet to produce a pink as dainty as would be desirable, though the older lines, long limited to orange rather than tangerine, are now giving some promising peach pinks. A number of orchid pinks with brighter, cleaner colors have been introduced recently. The yellow amoena remains elusive, as does the luminata version of the plicata pattern. Blue and purple amoenas, on the other hand, are particularly diverse, with falls ranging from the pale lavender wash of 'Ice Fairy' and 'Bit O' Afton' through the finely drawn lines of 'Pen Pal' to the deep violet-blue stripes of 'Snow Fiddler'. The lavender and white plicata 'Widget' ranks as the most used parent and has given rise to at least a dozen of the newer things including 'Gingham Blue' and 'Little Bluebeard' and the plicata 'Dani Grace'. Almost all of the early table irises now have one or more descendants and 'Pewee', 'Nambe', 'Siskin', 'Kinglet', 'Warbler', and 'Eversweet' have several. 'Hobo', 'Pixie', 'Playboy', and 'Spring Sprite', the tiniest table irises, with stems barely up to the lower limits of the class, are useful for reducing the stem size of larger sorts. It is too early to predict which of the modern varieties will prove the best parents, but 'Dainty Dancer', 'Blue Trimmings', 'Whispering Sprite', 'Jana White', and 'Dancing Gold' improve both form and color in their seedlings.

EXPERIMENTAL APPROACHES

In their search for improved colors, breeders are experimenting with a variety of approaches:
  1. Small tetraploid border irises, intercrossed. In addition to better substance and richer colors, tetraploid strains would have the advantage of much greater fertility than that of diploid hybrids with a background of many different species. However, in tetraploids selecting for decrease instead of increase in size is slow work. Flowers of miniature tall bearded measurements have been obtained, but oversized foliage and stout stems detract from the desired slender proportions.

  2. Small tetraploid border irises crossed with I. aphylla. This approach has met with considerable success, witness trim, dark Shrinking Violet. Seedlings of this type are well within the desired size range, btit stems though thin, are stiff rather than gracefully curved. The plants flower earlier than the usual miniature tall beardeds, but this is no disadvantage since it serves to extend the bloom period of the class. In the mulberry self, 'New Idea' (figure 2), aphylla lines and pink border iris lines have been combined.

  3. Small tetraploid border irises crossed with standard dwarfs. This is, of course~ the typical cross for intermediates, but some parental combinations give seedlings with small flowers and relatively thin stems, especially among the pinks and plicatas. Further crosses are needed to determine whether buds and branching can be brought closer to miniature tall bearded requirements.

  4. Diploid border beardeds or miniature tall beardeds crossed with standard dwarfs. A few experimental crosses suggest good possibilities here. Paul Cook reported more seeds from using the standard dwarf as the pod parent than from the reverse. Small flowers and thin stems approach the table iris goal, though branching may be only fair. Seedlings are less fertile than in (3), but the colors are particularly vivid.

SPECIES CROSSES

The tall forms of I. pallida do not enter into present day miniature tall bearded breeding, if they ever did-their height is too hard to reduce ip subsequent generations. A dwarf form, however, has been used, particularly with I. timofejewii to produce the small dark self Timpala and the lavender-purple 'Paltime', both with blue beards. Many seedlings have been raised from various clones of I. cengialti and I. illyrica because of their desirable satiny blues, but they, along with I. rudskyi, also blue, and purpleI. perrieri have yet to make their mark with modern named varieties.

Many clones of I. variegata are available, including recently collected brown blends and white and yellow variants with no anthocyanin. Red and yellow is no longer the despised color combination it once was, and I. variegata has, in fact, emerged as a source of superior reds. 'Quirk's' veined falls (figure 3), coalescing into a dab of red at the tip, resemble the original variegata pattern; at the opposite extreme 'Flashing Beacon' represents selection for solidly colored falls.

Of particular interest as a possible source of additional colors and patterns is venerable 'Honorabile' (figure 3), a Lemon variegate of 1840. Its two mutations of record, the erratic plicata 'Kaleidoscope' and the patchwork 'Joseph's Coat' (figure 3), both table irises, are only part of a series of mutants that includes the yellow self Sherwin-Wright, and 'Sans Souci, a paler variegata. Many single season changes in flower color have been reported for various members of the group; and Sherwin-Wright produces seedlings that reflect the patterns of both the plicata and variegata phases. Breeders' efforts to take advantage of this tendency to color change have so far been hampered by the limited fertility of the group. Possible causes of these mutations are presently under investigation (Witt 1971).

Many additional species have been tried in hybridizing, with some indication of the results that can be expected. I. reginae, essentially a little blue and white variegata with a faint echo of the fall pattern on the inside of the standards, gives suitably thin stems and a variety of colors and patterns. Unfortunately, it also bequeaths peculiar, awkward, wide-angled branching, a trait hard to breed out. Flower form, however, improves in the second and third generations, as the tan and lavender plicata 'Shady Sands' attests. I. imbricata, in the border iris range, looks promising as a parent for miniature tall beardeds; its influence may be seen somewhat obscurely in brown-purple 'Royal Thrush'. The effect of the pale yellow color, different from variegata yellow, is not fully known. Some of the collected imbricatas from Erevon, Armenia, are almost chartreuse-a green-toned table iris would delight the flower arrangers. Bright red violets of good carrying power are coming from I. furcata, which looks like a smaller I. aphylla but is diploid. Some of the seedlings are table iris size, some shorter. They tend to lack pollen, however, making further crossing difficult.

Dwarf species, too, have played a role in some miniature tall bearded developments. The golden tan 'Charlie Brown' (figure 3), from 'Siskin x ('Pink Ruffles' x I. mellita), was the first of this type. Rosy-violet blue-bearded 'Mellacata' is derived from I. mellita and I. furcata. A purple form of I. mellita is in the ancestry of pale ivory-pink 'Mother Mella', while the cream and red-brown plicata, 'Lunar Dust', traces back to both yellow and purple forms. Two white and violet amoenas have other dwarfs in their backgrounds-'Sweet Charlotte' has an Austrian pumila, and 'Drady's Girl', an unknown dwarf. I. attica contributes to the parentage of the yellow and white reverse bicolor, Gabi.

Paul Cook expressed the opinion that hybrids of I. flavissima and I. bloudowii might be useful in table iris breeding, but there is no evidence that anyone has tried this. There are as yet no miniature tall beardeds in the arilmedian category. None of the small C. G. White onco hybrids fall in the table iris size range, though some have been so listed in the past. The variety 'Oyez' perhaps comes closest. Species crosses can be expected to play a continuing role in the development of the miniature tall bearded class, though the appeal of some first generation species seedlings is still largely as breeders' flowers. Current registrations continue to be dominated by seedlings from the original table iris lines, and flower arrangers will find today's best miniature tall beardeds comparable in form to flowers of the other median classes.

Miniature tall bearded collections in commerce and in display gardens are being upgraded and demand for new varieties continues to increase as these charming and dainty flowers grow more and more popular with irisarians and the gardening public.

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"The World of Irises" continues with chapter 6, The Development of the Border Bearded Irises

Continued from Chapter 4 The Development of the Tall-bearded Irises

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For more information on historic Irises visit the Historic Iris Preservation Society at http://www.historiciris.org/

-- BobPries - 2015-12-01
Topic revision: r9 - 18 Feb 2018, Betsy881
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