Development Of The Spuria Irises (under construction)

Chapter 15, Spuria Irises, by Ben R. Hager, "The World of Irises" © 1978 AIS

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Early Spurias

Starting in Spain, in the western Mediterranean area, with occurrences as far north as a Danish island and a small colony on England's eastern coast, and as far south as North Africa and Corsica-sweeping in a band of varied width across Europe through Russia, Afghanistan and into China, is a diversified but not well studied group of irises assembled together in the series Spuriae of Apogon.

Spuria irises have flowers that superficially resemble the bulbous irises, especially I. xiphium, and share with this species the characteristic of producing drops of nectar on the perianth tube and spathes. Some of the smaller spurias resemble species in the Siberian group.

Horticulturally, the 14 or 15 species of spuria irises can be divided into two groups, a division important both in hybridizing and in the garden. In Turkey and eastward there are two, possibly three species that are late summer dormant and begin their new growth in late fall. These are the only species to count at 40 chromosomes and according to Hadley (1958) may be polyploid. Our modern hybrids are predominantly based on this group.

I. ochroleuca , with branched stems growing to 1.4 meters (4 feet), and 10-13 cm (4-5 inch) white flowers with prominent deep yellow signal areas on tucked falls, is the most commonly grown of these, species and has naturalized in many parts of the world.

I. crocea has 19-23 cm (5-6 inch) yellow flowers with lance-shaped (pointed) falls, grows to 1.5 meters (5 feet) and blooms late in the season. Only one collection has been made of this iris, over 100 years ago. It was then recorded that it grew in Kashmir, but no wild population has since been discovered or is now known. Although records show I. crocea (as I. aurea) as having been used in early parentages, no evidence remains of the pointed falls, a dominant expression in recently grown hybrids; it is probable that Monnieri, discussed later, is the predominant source of yellow coloring in our present-day varieties.

Seed collected by Haydar Bagda near Ankara, Turkey, was sent to Lee Lenz who grew from it a group of obviously related spurias with rather small, yellow flowers on 0.9-1 meter (36-40 inch) stems. Lenz (1963) suggests that this spuria is a possible species and has given it the interim name of "Turkey Yellow." Further collections and descriptions are necessary to give this iris definite status, but already its genes are well established in the development of our modem spurias.

The second and larger horticultural group of the spuria irises is made up of species that grow, in general, in more northerly areas and retain their green leaves throughout the summer, going completely dormant in the winter months. This group can be further subdivided into two parts: those growing to a height of less than 60 cm (24 inches), and those that attain heights of 60-100 cm (24-40 inches).

The shorter group is made up of species with a wide range of chromosome counts and had not entered the hybridizing field until recent work by Lenz combined species of both these "summer-green" groups. The resulting seedlings have proven partially fertile and will undoubtedly open up a whole new field of charming lower-growing garden varieties in the near future.

Members of the second and taller group of the "summer-green" spurias have counts of 38 and 44 chromosomes ( Rodionenko 1973). I. halophila grows to 1 meter (40 inches), and has 8-10 cm (3-4 inch) flowers with a color range from ecru, through grayed yellow to lavender. It also has white forms as does I. carthaliniae , which grows to 75 cm (30 inches)-its 8 cm (3 inch) flowers are usually blue with a veined pattern. I. maritima , I. klattii and I. demetrii (2n=38), have deep violet flowers. These species have been used with the 40-chromosome group in creating the spuria varieties of today, and it is from this group that the lavender and blue shades entered our hybrid lines (Lenz 1963, Lenz & Day 1963). ----

HISTORY

Late in the 19th century, Sir Michael Foster introduced the first spuria hybrids in England. Among these was one to which he gave the tandem name of "Monspur"-a combination of the names of the species that produced the hybrid: I. monnieri and I. spuria . Although the series Spuriae took its name from this central European species, it is a rather insignificant member with 22 chromosomes, and recent chromosome counts have indicated that it could not have been the species used in the 'Monspur' cross, with I. halophila or I. maritima being the more likely candidates.

The first American breeder of spuria irises was T. A. Washington who used 'Monspur' as well as. I. halophila in combinations with the 40-chromosome group, I. ochroleuca and I. monnieri. Only two of his last introductions of advanced generation hybrids, 'Blue Acres' and 'Monteagle', have played a part in the progression of spuria breeding. Most of Washington's hybrids had the characteristic of summer-green foliage inherited from the uses of 'Monspur' and I. halophila.

Later, Eric Nies made the cross of I. ochroleuca and 'Monspur', intercrossed the seedlings and never strayed outside of this tight inbreeding program. Since the summer-green growth pattern of 'Monspur' is a rather dominant feature in hybrids from such crosses, it is curious that none of the Nies inbred varieties ever showed this characteristic, tending more toward an exaggerated pattern of summer dormancy. Whatever the 'Monspur' that he used may have been, and curiously for such a hybrid it seems to have had 40 chromosomes, it did introduce the blue pigment into the line and formed the basis for production of a wide range of colors-brown, bronze cream and lavender blue-lacking only pure yellow self and white in the introduced varieties.

Recently, nonfading blue of a truer tone was brought into the spuria lines from crosses of 'Morningtide' and 'Golden Lady' with I. carthaliniae. Two such varieties are Hager's 'Neophyte', over 1.6 meters (6 feet) tall, and 'Protege', only 0.9 meters (3 feet) tall. Because of the work of Rodionenko of Russia with the spuria series, I. demetrii has recently been made available to breeders and is entering the breeding program bringing with it its deep violet coloring. Many of Ferguson's varieties show the influence of the summer-green inheritance from 'Premier'. 'Blue Spiderweb' is one of the best examples.

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MONNIER!

(I. monnieri) was discovered growing in a garden in France (figure 2). No wild habitat has been found, and although it was given a species designation at the time of its discovery, it is no longer considered a valid species. Lenz suggests from his investigations that certain morphological similarities of 'Monnieri' and "Turkey Yellow," particularly the short recurved style crests unlike those of either I. ochroleuca (figure 3) or I. crocea but strongly resembling those of Monnieri, would indicate that 'Monnieri' is indeed a hybrid between "Turkey Yellow" and I. ochroleuca, both wildlings from similar areas in Turkey (Lenz 1963).

Still in the area of postulation but backed by a strong family resemblance, 'Wadi Zem Zem' (figure 3) introduced by Milliken in 1943, appears to be a direct descendant of Monnieri. This variety won the first Nies award in 1956. It revolutionized the breeding of the spuria irises in two areas. First, it bequeathed to its offspring superior flower form-all of the better yellows in commerce can be traced back to Wadi, one or more times: Combs's Golden Lady, Walker's Oroville, Ferguson's Good Thunder, and Hager's Archie Owen (figure 3). Going further, the influence of Wadi is a force in the genetic background of varieties in all of the wide range of colors of the modem spuria irises.

Second, and possibly more importantly, Wadi Zem Zem carries a resistance to the troublesome virus infections of spuria irises; this resistance it passes on to many of its progeny. All spuria varieties that show resistance to virus damage can be traced directly back to Wadi Zem Zem, an important phenomenon for an iris series in which virus infection is the primary malady.

Walker Ferguson's breeding programs produced the most innovative directions in the development of our garden spurias (Ferguson 1964). An early cross with Monspur Premier (the name "Monspur," from Monnieri x spuria, was applied to many cultivars, some with obviously differing backgrounds) brought the strongly veined pattern of 'Premier' into a whole line of varieties based on the resulting 'Counterpoint', introduced in 1962, which lead to later quality creations such as Minneopa, McCown's 'Highline Sunset' and 'Hager's Sarong'. Also from this line appeared Ferguson's deep blues and violets, 'Fort Ridge' and 'Proverb'. Wine-red coloring first appeared among the Ferguson seedlings in 1973, in his 'Shift to Red', which he then crossed to Muhlestein's 'Red Step', a red-brown ;Monteagle; seedling. ;Red Oak; and ;Redwood Falls; were popular results of this line, and further work brought the beginnings of pink in 'Pink Candle', and the velvety deep purple, 'Purple Profundo'. Most of the color lines in spuria irises can be traced back to single origins, as yellow color is traced to ;Monnieri;. The browns and lavender blues are exclusive developments from the original Nies cross of I. ochroleuca x 'Monspur'.

Walker continued the Nies line, developing the great brown spuria 'Driftwood', winner of the Nies award in 1959. This in tum gave Ferguson's 'Baritone' in 1%5, B. Williamson's 'Antiqua', Niswonger's 'Butter Paddle', and the dark brown-black 'Crow Wing' from Ferguson in 1972.

The lavender-blue lines from Nies-Walker presented us with McCown's 'Highline Lavender' and Hager's 'Marilyn Holloway' and 'Clarke Cosgrove'. The entrance of orange-yellow coloring onto the scene was the immediate result of crossing "Turkey Yellow" with 'Wadi Zem Zem'.

A progression to better form can be found in the work of Ferguson and Hager from the original 'Elixir' through 'Intensity' to Hager's 'Eagle' and Ferguson's 'Forty Carats'. So far, true orange color seems to appear only in seedlings with small flowers, but the color is there. On the other hand, white, which had a good start with the white species I. ochroleuca, was lost along the way and is now reappearing from more complicated lines.

Milliken's 'White Heron', winner of the second Nies award in 1958, ,was a grandchild of I. ochroleuca; it caused quite a stir when it was introduced in 1948 because of its superior size and smaller yellow signals, but few marketed varieties have 'White Heron' in the parentage. 'Wakerobin', the only notable white from Ferguson, is from 'Color Guard', a Nies blue, by yellow 'Wadi Zem Zem'. The problem with the whites is that breeders have been trying to eliminate the yellow spot and by so doing achieve what they consider a more attractive white flower. In 1974, Walker introduced 'Sierra Nevada' which points in this direction. Another Nies blue, 'Ruth Nies Cabeen', which is in the background of this white, has tended to reduce the signal areas in both its white and its blue seedlings. New whites with disappearing signals are also showing up in lines combining 'Wadi Zem Zem' with lavender-blue flowers, and in seedlings with I. carthaliniae in the background.

Breeders are also working for more ruffling, which has obviously been slow of development in spuria irises. Walker's 'Lydia Jane' and Hager's 'Ila Crawford' are impressive whites with thisfeature. ----

CROSS-POLLINATION OF SPURIAS

Spurias are readily self-pollinated, however, the anthers do not open as early as they do on other beardless irises. If the bud is beginning to open, observe the anthers. If they are closed or just opening, you are probably still safe, but it is best to open a still closed but fully developed bud, and remove both anthers and falls. This should be all that is necessary to protect the cross. Bagging is not a requisite unless the cross is being made for scientific experiment. The stigma may not be mature at this time, so if you make the pollination immediately, chances are about 50-50 that it will not take. Repeat the pollination the next day, or wait until then to make it. ----

CULTURE

Spurias must have full sun and good drainage. Most of the garden hybrids have a late summer-dormant period. Too much moisture combined with summer heat causes a rot that takes the new growing points, and this applies to the summer-green types also. Irrigation as necessary should be applied through July for best plant development, but should be withheld after that until fall growth begins. Foliage of the summer-dormant types can be cut back to the ground for garden neatness after the first of August without harming the plant growth.

Spuria irises do best in neutral to slightly alkaline soil. Some gardeners claim sparse bloom unless sulfur is added to their soil, but it may be that such soils are over alkaline.._ In California, with Mediterranean conditions, spuria irises give peak performance; here the soil is on the alkaline side as is the irrigation water.

Spuria irises are heavy feeders, rewarding with superior plants and flower stalks the grower who incorporates into his soil plenty of barnyard manures and/or commercial fertilizer. If fertilized annually, clumps will persist and bloom for years-10 to 15 year clumps are not unusual, and eventually spread to as much as 1.5 m (5-6 feet). ----

PROBLEMS IN GROWING THE SPECIES

Except for the summer-dormant (or 40-chromosome) types, most spuria species are difficult and unpredictable. Often, from seed, they will grow lustily and bloom, then the entire clump will immediately die, with an appearance resembling the scorch of bearded irises, with roots affected first. The 44-, 38- and 22-chromosome groups (I. halopliila, carthaliniae, klattii, demetrii, and spuria) are little grown in the east, and are difficult to maintain in the western states; of the shorter species, only I. graminea is commonly grown in the east. In the west, the smaller types are sometimes erratic. I. graminea, urumovii and brandzae are less often completely lost; kernerana and sintenisii are not as cooperative. ----

DISEASES OF SPURIA IRISES

Virus is the most worrisome of spuria iris diseases (Barnett & Brunt 1975). Evidence of infection-striping in the foliage, dark flecking or watermarks (teardrops) in the flowers and distortion of petals, varies from heavy (susceptible) to light or unobservable (resistant). Its expression in the same done varies from season to season. The problem with the disease is one of disfigurement. It is almost never fatal among the named cultivars, and seldom very debilitating under good cultural conditions. A treatment or cure is unknown, but resistance can probably be bred into spurias by using virus-resistant parents and making careful selections of seedlings for future breeding.

Mustard seed fungus is devastating in spurias. The combination of warm weather and moisture, especially in southern and western states, provides this fungus with ideal conditions for swift propagation. Soaking rhizomes in 5 percent sodium hypochlorite solution and thoroughly incorporating Terraclor1 into the soil before planting are effective controls (chap. 21).

Insects are a minor problem. However, spuria irises produce copious amounts of nectar at the base of the•perianth tube inside the spathe valves, and this attracts entire populations of ants and flying insects. Where there are ants, there are aphids, and the commodious spathe valves and leaf bases house them en masse. For ladybugs and green lacewings, an aphid is the gourmet's delight, but the spathes and tightly wrapped leaf bases make it difficult for predators to enter these potential banquet halls. Systemic insecticides are effective but also poison beneficial insects.

Aphids in the spathes can distort a developing seedpod, so the spathes should be removed after the flower has withered; they are needed to support the flower until that time. ----

THE SEED AND SEEDLINGS

The fresher the seed when planted the better will be the germination. Remove the seed from the pod when the spurs on the tip of the pod begin to separate, and plant immediately. If seed is aflowed to dry out, germination may,be delayed as much as a year. In colder areas protection will be necessary since some germination will take place before winter and the seedling plants should not be subjected to temperatures under -6.7 degrees C (20 degrees F). Most of the seed will wait.until spring to germinate. A gritty well-drained mixture is best to plant the seed in. Under the gritty layer it is advisable to have a layer of rich soil high in humus or manure as well as commercial fertilizer. Damping-off can be a problem in the seedling bed. Terraclor or the related Terraclor Super X can be mixed into the soil before planting for prevention, or damping-off control chemicals can be used as a drench when the disease appears, but this is usually too late to save all the plants.

Spuria seedlings require special treatment. Transplanting out of the seed bed should be done in early fall, at the same time as the adult plants, with winter protection for cold climates. Choose a space where they can remain until they bloom-at least two years. Due to the fall planting and the naturally slower maturing of the seedlings of spuria iris, it will take a year or more longer for the spuria seedlings to bloom than for bearded iris seedlings2 (chap. 22). ----

SPURIAS FOR COLD CLIMATE GARDENS

The modern spuria hybrids have been bred predominantly in warm climates, and although the beautiful new developments are perfectly hardy in cold-climate gardens, they do not always perform well there. Perhaps because they are deprived of summer dormancy in areas with plentiful summer rains, many show a habit of producing large clumps of foliage with few if any bloomstalks. It seems probable. that plants more suited to colder and wetter climates could be bred without much difficulty. The spurias are strong and colorful plants in the garden, and their handsome flowers are useful for cutting, though not as long-lasting as those of the florists' Dutch irises, which they very much resemble.

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

-- BobPries - 2016-01-12
Topic revision: r4 - 12 Feb 2016, BobPries
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